Red, White and Blue Sheet Cake

When summer rolls around, there is nothing quite like a backyard barbecue filled with good friends, smoky mains, and a show-stopping dessert. This Red, White, and Blue Sheet Cake is the ultimate patriotic crowd-pleaser.

Whether you are hosting a neighborhood bash or bringing a dish to a potluck, this cake is festive, incredibly moist, and guaranteed to disappear fast.

Best of all? It’s completely customizable. Below, you’ll find instructions to make it entirely from scratch, along with some clever semi-homemade shortcuts if you are pressed for time.

Why You’ll Love This Recipe

Perfect for Crowds: Baking in a sheet pan means plenty of slices to go around.
Patriotic Flare: Vibrant red, white, and blue piped buttercream buttercream naturally mimics the classic look of Old Glory.
Flexible Prep: Choose between the rich flavor of homemade or the speed of a boxed mix.
Holiday Versatility: It’s the perfect centerpiece dessert for Memorial Day, the 4th of July, and Labor Day!

What You’ll Need to Make This Sheet Cake

To get that perfectly plush, ultra-moist, bakery-quality crumb, using the right ingredients at the right temperature is key. Here is what you need to gather for the ultimate scratch-made base:

All-Purpose Flour: This provides the essential structure for your sheet cake.
Baker’s Tip: For an even softer, fluffier texture, you can swap it for cake flour. If you don’t have any on hand, make your own: for every cup of all-purpose flour, remove two tablespoons of flour and replace them with 2 tablespoons of cornstarch.
Granulated Sugar: Adds the perfect amount of sweetness and locks in moisture.
Baking Powder & Baking Soda: Our leavening agents that give the cake its lift. Always double-check that your leaveners are fresh and not expired so your cake doesn’t fall flat!
Fine Sea Salt: Balances the sweetness and enhances all the other flavors. (Pink Himalayan salt also works beautifully here.)
Unsalted Butter: Using unsalted butter allows you to completely control the salt content. It absolutely needs to be at room temperature so it creams properly with the sugar. Take it out a couple of hours before baking—it should leave a slight dent when you press it with your finger. In a pinch? If you forgot to take it out, zap it in the microwave for about 15–20 seconds. Just be careful not to melt it completely!
Pure Vanilla Extract: Infuses the batter with that classic, warm bakery flavor. (Personally, I love grabbing the big bottle of pure vanilla extract from Costco for the best quality and value!)
Full-Fat Buttermilk: Keeps the crumb incredibly tender. Make sure it is at room temperature before mixing, and avoid lower-fat or nonfat versions if you want the richest flavor. DIY Buttermilk Hack: If you don’t have buttermilk, add 2 teaspoons of white vinegar or lemon juice to a liquid measuring cup, then fill the rest of the cup with whole milk to the 1-cup line. Stir and let it sit for 5 minutes until slightly curdled.
Full-Fat Sour Cream: The ultimate secret weapon for a dense, ultra-moist cake. Just like the dairy, bring this to room temperature by pulling it out of the fridge an hour ahead of time.
Large Eggs: Room-temperature eggs emulsify effortlessly into the batter, ensuring you don’t overmix your cake.
Festive Extras (Optional): Throw in some patriotic sprinkles or a dash of blue and red edible glitter to bring that extra “firecracker” energy to the presentation!

What You’ll Need for the Ultimate Vanilla Bean Buttercream

A show-stopping sheet cake deserves an equally incredible frosting. This vanilla bean buttercream is rich, fluffy, and speckled with beautiful vanilla bean flecks. Here is what you need:

Unsalted Butter: Standard for a great buttercream. Ensure it is softened to room temperature so it whips up into a smooth, cloud-like consistency without any lumps.
Fine Salt: Just a pinch to cut through the intense sweetness of the sugar and balance the rich dairy.
Pure Vanilla Extract & Vanilla Bean Paste: Using vanilla bean paste is an absolute game-changer—it adds those gorgeous, gourmet black flecks and a deeply concentrated flavor. Baker’s Tip: My absolute favorite brand is Nielsen-Massey (you can grab it easily on Amazon), but Trader Joe’s also carries a great seasonal vanilla bean paste! If you don’t have paste on hand, don’t worry—it’s not the end of the world. You can easily substitute it 1:1 with high-quality pure vanilla extract.
Heavy Whipping Cream: This is the secret to getting that ultra-creamy, spreadable bakery texture. If you are in a pinch, whole milk will work as a substitute, but heavy cream yields the fluffiest results.
Powdered Sugar: Also known as confectioners’ sugar, this provides the structure and sweetness for your frosting. P.S. — Save yourself some time: You do not need to sift your powdered sugar for this recipe! A high-powered mixer will effortlessly smooth out any tiny clumps while whipping.
High-Quality Food Coloring: While you can use any standard brand from the grocery store, I highly recommend using AmeriColor Gel Paste or Colour Mill Oil-Based Food Colouring (both are easily found on Amazon). Gel and oil-based colorings are fantastic because they are highly concentrated—you get incredibly vibrant red and deep royal blue tones without watering down your batter or frosting!

Baking Supplies & Tools Needed

Having the right tools ready to go makes the decorating process smooth and stress-free. Here is exactly what I used to bring this firecracker look together:

Piping Bags: You’ll want to have several bags ready to go so you can easily switch between your different colors and piping tips. I grab mine in bulk from Amazon (For this specific cake design, I used exactly 7 piping bags!)
Piping Tips: To get those gorgeous, bakery-style textures and borders, you will need a few specific tips: one 1M tip, one 4B tip, and two 8B tips. You can easily find these at Michaels.
9×13-Inch Baking Pan: Any standard metal, glass, or even a disposable aluminum pan will work perfectly fine here. However, if you want perfectly straight edges and an even bake, I absolutely love and highly recommend using Fat Daddio’s anodized aluminum pans.

How to Make the Red, White & Blue Sheet Cake (Step-by-Step)

This recipe is incredibly straightforward, but the key to success is keeping an eye on your mixing time. Follow these steps for a perfectly plush, beautifully marbled cake.

Step 1: Prep and Preheat

Preheat your oven to 350°F (175°C). Generously grease your 9×13-inch baking pan (or line it with parchment paper for easy removal) and set it aside.

Step 2: Cream the Base

In the bowl of a stand mixer fitted with the paddle attachment (or using a large bowl and a handheld mixer), cream the softened butter and granulated sugar together on medium speed. Beat for a few minutes until the mixture is light, fluffy, and pale in color.

Step 3: Add the Wet Ingredients

Add the room-temperature eggs one at a time, followed by the pure vanilla extract, beating until smooth.

Pro Tip: Stop the mixer once or twice during this step to scrape down the sides and up the bottom of the bowl with a spatula to ensure everything is evenly incorporated.

Next, add the full-fat sour cream and beat on medium-high speed until completely combined.

Step 4: Whisk and Alternate the Dry Ingredients

In a separate large bowl, whisk together your all-purpose flour, baking soda, and fine salt.

With the mixer on low speed, add about half of the flour mixture and mix for just 5 seconds. Pour in half of the buttermilk and mix for another 5 seconds. Repeat this process with the remaining flour, followed by the remaining milk. Mix on low just until the batter is combined and smooth. Do not overmix, or the cake will lose its tender crumb!

Step 5: Color the Batter

Divide your cake batter evenly into three separate bowls.

Bowl 1 (Red): Mix in your AmeriColor Super Red gel paste until you achieve a vibrant holiday red.
Bowl 2 (Blue): Mix in your Colour Mill Cobalt Blue oil-based coloring for a rich, royal blue.
Bowl 3 (White): Leave this batter plain.

Step 6: Create the Marble Effect

To get that perfect festive marble look without the colors turning into a muddy purple:

Drop small, alternating spoonfuls of the red, white, and blue batters randomly across your prepared 9×13 pan. Scatter them well so the colors are evenly distributed.

Once all the batter is in the pan, take a butter knife or a toothpick and gently swirl the colors together in a zig-zag pattern. Step away from the knife early—do not over-swirl!

Step 7: Bake and Cool

Bake for 45 to 50 minutes, or until the top is lightly golden brown and a toothpick inserted into the very center comes out clean.
Remove the cake from the oven and allow it to cool completely right in the pan. Do not attempt to frost it until it is entirely cool to the touch! While you wait, it’s time to whip up that vanilla bean buttercream.

How to Make the Ultimate Vanilla Bean Buttercream

This frosting is incredibly luxurious, fluffy, and flecked with beautiful vanilla bean specks. Because we aren’t sifting the sugar, letting the mixer do the work during the final whip is the secret to getting it perfectly smooth.

Step 1: Beat the Base

In the bowl of a stand mixer fitted with the paddle or whisk attachment (or using a large bowl and a handheld mixer), beat the softened unsalted butter on medium speed for about 2 minutes. You want it to be completely smooth, creamy, and light in color.

Step 2: Add the Aromatics & Dairy

Turn the mixer down to low speed. With the motor running, slowly pour in the pure vanilla extract, vanilla bean paste, heavy cream, and fine salt. Mix just until combined.

Step 3: Gradually Add the Sugar

Keeping the mixer on low speed, slowly add the powdered sugar a little bit at a time. Adding it gradually prevents a giant cloud of sugar from escaping the bowl!

Step 4: The Big Whip

Once all the powdered sugar is incorporated, scrape down the sides of the bowl. Increase the mixer speed to high and beat the frosting for 3 full minutes. This builds structure, whips in air for a cloud-like texture, and smooths out any tiny sugar clumps.

Step 5: Tweak to Perfection

Every kitchen environment is a little different! Before loading up your piping bags, check your consistency and adjust if needed:

Too thin? Add a few more tablespoons of powdered sugar.
Too thick? Splash in a tiny bit more heavy cream (a teaspoon at a time).
Too sweet? Mix in an extra pinch of fine salt to cut the sweetness.

Yield: This recipe makes about 6 cups of frosting—plenty for a thick layer of base frosting and all your decorative patriotic piping!

How to Decorate the Cake (The Fun Part!)

The secret to this stunning patriotic design is a professional trick called double-bagging. It allows you to switch piping tips effortlessly without making a mess or wasting frosting. Here is exactly how to bring this star-spangled beauty to life:

Step 1: Color Your Frosting

Divide your 6 cups of vanilla bean buttercream evenly into three separate bowls (about 2 cups per bowl).

Bowl 1 (Red): Tint using your AmeriColor Super Red gel paste.
Bowl 2 (Blue): Tint using your Colour Mill Cobalt Blue oil-based coloring.
Bowl 3 (White): Leave plain.

Step 2: Set Up Your Piping Bags (The Double-Bag Trick)

The Frosting Bags: Snip the tips off 3 piping bags. Fill one with red frosting, one with blue, and one with white. Set them aside.
The Tip Bags: Snip the tips off your remaining piping bags and drop your metal tips inside them.
The Assembly:
- Slide your blue frosting bag inside the bag fitted with the 1M tip.
- Slide your red frosting bag inside a bag fitted with an 8B tip.
- Slide your white frosting bag inside the other bag fitted with an 8B tip.
- (Keep your 4B tip ready in its own empty piping bag—we will use it at the end!)

Step 3: Pipe the Blue Field & Red and White Stripes

Now that your bags are loaded, it’s time to create the flag pattern right on top of your cooled, marbled sheet cake:

The Blue Field: Grab your blue bag (1M tip) and pipe 9 beautiful, tight rosettes in a rectangle in the top-left corner of the cake.
The First Stripe: Grab your red bag (8B tip). Starting at the very bottom edge of the cake, pipe a clean row of open-star dollops from left to right.
The Second Stripe: Grab your white bag (8B tip). Right above your red row, pipe a row of white dollops, working this time from right to left.
Repeat: Continue alternating rows of red and white stripes until you reach the top of the cake, piping right around your blue rosette rectangle.

Step 4: Add the Finishing Touches

To complete the flag look, pull your white frosting bag out of the 8B bag and slide it into the empty bag fitted with the smaller 4B tip.

Pipe tiny white “stars” or dollops directly on top of your blue 1M rosettes.

Take it up a notch: If you want to give this cake true firecracker energy, finish it off with a handful of patriotic sprinkles and a dust of gold edible glitter like I did!

How to Slice, Serve, and Store

Once your masterpiece is complete, it’s ready to slice and serve!

Yield / Serving Size: Yields 12 large bakery-sized slices, 20 to 24 standard slices, or up to 30 smaller party-sized squares.
To Store: Cover the cake tightly. Leftovers can be kept at room temperature for up to 3 days, or stored in the refrigerator to keep the frosting firm and fresh for up to 5 days.

Pro-Tips for the Perfect Firecracker Sheet Cake

To make sure your cake turns out incredibly moist and your decorating is completely stress-free, keep these essential baker’s rules in mind:

Embrace Room Temperature Ingredients: Seriously, don’t skip this! All of your refrigerated items—the butter, eggs, sour cream, and buttermilk—need to be at room temperature. This ensures the batter emulsifies smoothly and evenly without separating.
Watch the Mixing Time: Once you add the dry ingredients to the wet ingredients, mix only until just combined. Over-mixing the batter over-develops the gluten, which transforms a soft, fluffy cake into something tough, dry, and dense.
Never Frost a Warm Cake: Patience is a virtue here! Make sure to allow the cake to cool completely to the touch before you even think about grabbing your piping bags. If the cake is even slightly warm, it will melt the butter in your buttercream, causing your gorgeous designs to slide right off.
Nailed the Butter Texture? For a flawless, cloud-like frosting, your butter must be perfectly softened to room temperature before whipping. If the butter is too cold, you’ll end up with frustrating tiny lumps in your buttercream that can clog your piping tips.
Chill for Clean Cuts: If you want your piped buttercream stars and rosettes to hold their shape perfectly when slicing, pop the completely decorated cake into the refrigerator for an hour before serving. Chilling helps the buttercream set firmly to the cake, giving you those clean, picture-perfect bakery slices!

Frequently Asked Questions

Prep & Storage

Can I make this cake in advance?
Yes! You can easily split the work over two days—in fact, I always like to bake the cake base one day and decorate it the next. You can store the baked cake and the buttercream separately in the fridge for a few days (wrapped tightly). Just remember to pull the buttercream out a few hours before decorating to let it soften, and give it a quick re-whip in your mixer to bring back that perfectly spreadable consistency. You can also store the completely decorated cake in the fridge for up to 5 days.

How do I store leftover frosting?
Leftover buttercream can be stored in a tightly sealed container in the fridge for up to 7 days. Baker’s Tip: Keep it far away from pungent foods like seafood, as butter easily absorbs surrounding odors! You can also freeze buttercream for up to 3 months. Thaw it overnight in the fridge, bring to room temperature, and re-whip before using.

How do I store leftover cake?
Cover and store leftover cake at room temperature for up to 3 days or in the fridge for up to 5 days. Want to save it for later? Both frosted and unfrosted cake slices freeze beautifully for 2–3 months. Wrap them thoroughly in a layer of plastic wrap followed by aluminum foil. Thaw overnight in the refrigerator and bring to room temperature before serving.

Recipe Variations & Shortcuts

Can I turn this recipe into a 2-layer cake?
Yes! Grease two 8-inch or 9-inch round cake pans and line the bottoms with parchment paper rounds (greasing the parchment too) for a seamless release. Divide the batter evenly between the pans and bake at 325°F (163°C) for 27 to 30 minutes, keeping a close eye on them and testing with a toothpick.

Can I turn this recipe into a Bundt cake?
Absolutely. Generously grease your Bundt pan and bake at 325°F (163°C) for 25 to 35 minutes, checking the center with a toothpick for doneness.

Can I turn this recipe into cupcakes?
Yes! Line a cupcake pan with liners and fill them 2/3 full. (I love using a standard baking scoop for regular cupcakes and a mini scoop with mini liners for bite-sized treats). Bake at 350°F (175°C) for 14 to 19 minutes. This recipe yields about 22 regular-sized cupcakes.

Can I make a sprinkle cake instead of a marble cake?
Yes! To transform this into a fun confetti cake, simply skip the food coloring step and fold about 2/3 cup of sprinkles into the final batter. Important: Stick to standard rainbow “jimmies” (the rod-shaped ones). Avoid nonpareils (the tiny round balls), as they will bleed their color into the white batter while mixing. Save the nonpareils for the top of the frosting instead!

Can I just make a plain vanilla cake and not marble it?
Absolutely! If you want a classic, solid vanilla cake base instead of the marbled look, simply skip dividing the batter in Step 5. Leave the entire batch of batter plain white, pour it directly into your greased 9×13-inch pan, and bake as directed. It will still have that incredibly plush, moist crumb, and your piped red, white, and blue flag frosting on top will provide all the patriotic flair you need!

Can I make this with a store-bought cake mix?
You sure can. Grab any vanilla or white boxed cake mix and prepare the batter according to the package instructions. From there, jump straight to Step 5 of our recipe guide to color and marble your batter, or just fold in jimmies for a shortcut sprinkle cake. Bake according to the times listed on the box.

Can I use store-bought frosting?
Yes! Pick up 2 to 4 tubs of your favorite store-bought vanilla frosting. Then, skip directly to Step 8 of the instructions to divide, color, and pipe your patriotic flag design.

How to Color Cake Batter & Buttercream (The “Resting” Trick for Deep Reds and Blues)

When working with highly concentrated colors like AmeriColor Gel and Colour Mill Oil-Based food coloring, a little bit goes a very long way. Because you want a vibrant, firecracker look rather than pastel shades, here is exactly how to gauge and add your coloring for both the batter and the buttercream:

For the Marbled Cake Batter

Cake batter is naturally opaque and pale yellow, meaning you have to add a bit more color to overcome the yellow tint of the eggs and butter.

The Starting Amount: Start with ¼ to ½ teaspoon of color for your 2-cup bowl of batter. For AmeriColor gel, this is about 4 to 6 large drops. For Colour Mill, give the bottle a good shake and add a slow squeeze.
The Goal: Mix thoroughly. The batter should look slightly brighter and darker than your desired end result, as colors can fade slightly or look more subdued once the flour bakes and expands.

For the Vanilla Bean Buttercream

Buttercream is much easier to tint than batter, but colors deepen and intensify significantly as the frosting sits and the sugar absorbs the moisture/oil.

The Starting Amount: Start small! Add just 2 to 3 drops of color to your 2-cup bowl of buttercream.
The “Resting” Trick: Mix the color in completely. If it looks a shade or two lighter than you want, stop and let it sit for 10 to 15 minutes before adding more. You will be amazed at how much darker and richer the red and blue become just by resting on the counter!
Adjusting: If it’s still too light after resting, add 1 more drop at a time. It is much easier to add color than it is to fix a bowl of frosting that has turned too dark.

3 Crucial Color Tips

Watch Out for “Bitter” Red: If you use low-quality grocery store red dye, adding enough to get a true red can make your frosting taste bitter or metallic. Because you are using AmeriColor Super Red, you won’t have this problem! It gives a deep red without altering the delicious vanilla bean flavor.
Prevent Blue Teeth: To get a rich Cobalt Blue without staining your guests’ smiles, start with your 3 drops of blue, let it deepen, and stop once it hits a nice royal blue.
Keep the White Bright: Your plain buttercream will have a gorgeous gourmet look from the vanilla bean paste flecks, but if your butter makes the frosting look a little too yellow, you can add a tiny drop of white food coloring (like AmeriColor Bright White) to brighten up the “white stripes” and “stars” of your flag!

If you make this Sheet Cake for your holiday weekend, I want to see it! Take a picture and tag me on Instagram or leave a comment and rating down below. Happy baking, and have a safe, wonderful, and delicious holiday!

Red, White & Blue Sheet Cake

Level: Intermediate

By: Tammie

June 29, 2023
12
4 hr
Print this

Ingredients

Vanilla Cake:
1 cup (2 sticks) unsalted butter, at room temperature
1 and 1/2 cups granulated sugar
3 eggs, at room temperature
1 Tablespoon pure vanilla extract
1/3 cup sour cream, at room temperature
3 cups all purpose flour
1 teaspoon baking powder
1/2 teaspoon baking soda
1/2 teaspoon salt
1 cup buttermilk, at room temperature
Red & Blue Food Coloring
Sprinkles (optional)
Edible Glitter (optional)
Vanilla Bean Buttercream:
1 and 1/2 cups (3 sticks) unsalted butter, at room temperature
1 Tablespoon pure vanilla extract
1 Tablespoon vanilla bean paste
1/4 teaspoon salt
1/2 cup heavy cream
2 lbs powdered sugar (1 bag)
Supplies:
9x13 inch sheet pan
Pipping bags
Pipping tips 1M, 4B and two 8B

Directions

Step 1: Prep Pan & Preheat: Preheat the oven to 350°F. Generously grease a 9×13-inch cake pan.
Step 2: Cream the Wet Ingredients: In a large bowl using a handheld mixer or stand mixer fitted with a paddle attachment, cream the softened butter and sugar on medium speed. Beat until light, fluffy, and pale in color. Beat in the eggs and vanilla until smooth, stopping the mixer to scrape down the sides and up the bottom of the bowl a couple of times. Finally, beat in the sour cream on medium-high speed until combined.
Step 3: Whisk Dry Ingredients: In a separate large bowl, whisk the flour, baking soda, and salt together.
Step 4: Combine the Batter: Pour half of the flour mixture into the creamed butter mixture and beat on low speed for just 5 seconds. Pour in half of the milk and beat on low speed for 5 seconds. Repeat with the remaining flour, then the remaining milk, mixing just until combined and smooth. Do not overmix!
Step 5: Color & Marble: Split the batter evenly into three bowls. Tint one bowl red (using AmeriColor Super Red) and one bowl blue (using Colour Mill Cobalt Blue). The third bowl remains plain white. Drop alternating small spoonfuls of each color randomly into the pan. Once all the batter is added, use a butter knife or toothpick to gently swirl the colors together. Do not over-mix or the colors will muddy!
Step 6: Bake & Cool: Bake for 45–50 minutes, or until the top is lightly browned and a toothpick inserted in the center comes out clean. Remove from the oven and allow the cake to cool completely in the pan before decorating.
Step 7: Whip the Vanilla Bean Frosting: While the cake cools, make the frosting. Beat the butter on medium speed until light and fluffy (about 2 minutes). With the mixer running on low, add the vanilla extract, vanilla bean paste, heavy cream, and salt. Slowly add the powdered sugar, then increase the mixer to high speed and beat for 3 full minutes. To adjust consistency: Add more powdered sugar if too thin, more cream if too thick, or an extra pinch of salt if too sweet. (Yields about 6 cups).
Step 8: Prep the Piping Bags: Split the buttercream evenly into three bowls. Tint one red and one blue, leaving the third white. Fill three separate piping bags with the colored frostings and snip the tips off. Drop your metal tips into a second set of empty piping bags and snip those tips. Double-bag them: Slide the blue bag into the 1M tip, the red bag into an 8B tip, and the white bag into the second 8B tip. (Keep your 4B tip ready in its own empty bag).
Step 9: Pipe the Flag Design: The Blue Field: Use the 1M blue bag to pipe 9 rosettes in the top-left corner of the cake. The Red Stripes: Take the 8B red bag and pipe a row of star dollops along the very bottom edge of the cake, working from left to right. The White Stripes: Take the 8B white bag and pipe a row directly above the red row, working from right to left. Repeat alternating rows until the cake is filled. The Stars: Slide the white frosting bag out of the 8B setup and drop it into the 4B tip bag. Pipe tiny white stars on top of your blue rosettes. Optional: Finish with patriotic sprinkles or gold edible glitter!
Step 10: Serve & Store: Slice and serve! Yields 12 large bakery-sized slices, 20 to 24 standard slices, or up to 30 smaller party-sized squares. Cover any leftover cake tightly and store it in the refrigerator for up to 5 days.