American Flag Cake

Last Updated December 17th, 2022 at 08:29 pm by Lisa

Bake a patriotic American Flag Cake with red, white, and blue marbled cake inside and bakery-style frosting.

Always a party crowd pleaser and a great way to show your patriotism for the Fourth of July, Memorial Day, Summer cookouts, or a picnic...

As a young girl, I still remember when my Aunt Barbara made an American Flag cake. She shared it at a picnic and fireworks at Lacy Park in Los Angeles

So for years, I made a festive flag cake original recipe from Ina Garten in my home on July 4th for friends and family. In the past, I would also sometimes buy bakery-style frosting and bake one in a sheet pan size. One year I ran out of time, and let everyone help decorate the cake during the July 4th party! 🇺🇸

People loved it, and I kept it simple. But I saw these marbled cakes and thought how cute it would be as a colorful surprise inside? Then I set out to frost it with homemade fluffy frosting. Canned frosting and the buttercream I normally make are too sweet and not the right "spreadability".

So I set out to create a smooth, creamy, not-too-sweet frosting as they make in bakery shops. And here is what awaits, it is now my favorite cake...

American Flag Cake Recipe

Marbled Cake

• white vanilla boxed cake mix
• water vegetable oil eggs called for on the box
• red food color or gel
• blue food color or gel
• fresh raspberries (or fresh strawberries)
• fresh blueberries

Frosting

• salted butter - room temperature
• vegetable shortening
• powder sugar (confectioners' sugar)
• hot water
• vanilla extract
• almond extract (optional but great!)

Prep The Pan

1. Put a few drops of vegetable oil in the bottom of your cake pan. Next, line with parchment paper cut to fit the bottom of the pan.
2. This prepared pan will release the cake easier and makes for a faster clean up. If you are serving right from the pan and not removing the cake to decorate it, don’t line the pan of course!

Mix The Cake Frosting

1. Beat soft butter and shortening in a mixer on medium-high speed until creamy for 5 minutes.
2. At low speed, add powder sugar 1 cup at a time until smooth.
3. On high speed, mix in vanilla, almond extract, and hot water for 5 minutes until fluffy and smooth. This frosting holds really well at room temperature for a few hours.

Bake The Flag Cake

1. Stir your boxed cake mix and ingredients in a medium bowl, the bowl of a stand mixer with a paddle attachment, or using a hand mixer on medium speed.
2. Deeper pans might need more batter. I used a deeper pan that is 3 inches deep, so I mixed up 2 boxes of cake batter. Most standard pans are 2 inches deep.
3. In a small bowl place 1-2 cups of batter and scrape down the sides of the bowl as you go, stir in red food color until it’s the red you like. In another small bowl, place 1-2 cups of the batter; stir in blue food color until it’s the blue you like. Save 1-2 cups of plain white batter.
4. Now, pour batter in dollops into the prepared baking pan alternating from red, white and blue. Try to place the batter on top of each area, it will begin to spread out.
5. When all the batter is in the pan, use a skewer to pull lines from the center outward, and then do some slight swirls around the pan. This helps create the marble design. Rap the pan down on the counter to help level the batter and pop any bubbles in the batter that would make it bake unevenly.
6. Heat oven to 325 degrees. Bake in the center of the oven according to your box mix directions. Most classic boxed mixes require a 350-degree oven for 28 minutes for a regular 9 x 13 pan. If you use a pan deeper than 2 inches, reduce the baking temperature to 325 degrees and bake longer for 55 minutes. Check with a toothpick, if it comes out clean the cake is done.

Decorating A Flag Cake

1. Cool it for 10 minutes in the pan, then remove it to a wire rack to finish cooling. Cool it in the refrigerator for at least two hours or preferably overnight before decorating. I like to bake one day, then decorate them the next. This helps release the steam in the cake and the frosting holds on when chilled, otherwise, it tends to melt.
2. Place a dollup of frosting on a small piece of cardboard or a tray, and set the cake on top. This keeps it from sliding around while decorating and makes it easier to transfer cakes to a party.
3. Frost the entire cake with the vanilla buttercream using a small offset spatula. Smooth out the frosting in an even layer as best you can all over the top and sides.
4. For the flag design, use the tip of a small knife and draw a line about 5 inches long and 4 inches tall for the blue part of the flag in the upper left corner. Place blueberries in that box, pick the best larger ones and place them with the smooth side up.
5. Starting at the top edge, use large raspberries pointed up and make long rows of red, leaving a 1" white stripe in between each row of raspberries.
6. Fill a large pastry bag with a large 1M large star tip and the frosting. To fill the piping bag, rest the piping bag in a tall sturdy jar or glass and pull the piping bag down around the edge of the container, this helps to fill it up the bag. Pipe stars on blueberries for the stars of the flag working in slightly offset rows like the American flag.
7. For the white stripes of the flag, pipe stars in between rows of raspberries, and decorate the sides if you wish. You will have some frosting leftover, it freezes great in a zip-top bag, and can be used for another dessert like cupcakes.
8. The cake will hold well overnight in the refrigerator for 1 day, and possibly 2 days if your berries are really fresh. I would decorate either the day of your party or the night before. I have also had guests decorate it during the party which was SO much fun!
9. The best way to keep any leftovers is to cover it on the board with plastic wrap and put the entire thing in the refrigerator. Eat up the leftovers within a couple of days.

Flag Cake Decorating Tips

Baking Pans - You can bake this in a sheet pan, glass 9 x 13 dish, or metal cake pan. If you use a pan deeper than 3 inches, you will want to lower the temperature from 350 down to 325 degrees and bake it longer, about 50 minutes. Also, be sure to line the pan with parchment, it makes taking the cake out so much easier, and in one piece. 🍰 Sheet cakes are already in the shape of a flag, so this is a simple bake.

Batter - Coloring the batter is really easy. PRO TIP: Be sure to use bowls that won't stain with the dye. To create the marble look, just work to put big dollops on top of each other, with lots of white batter all over. Then use a chopstick to pull outward from the center and then in a circle. This makes the swirls you want! 🥣

Baking - You can bake a day ahead, and keep it chilled in the fridge. You will want the cake very cool before you frost it!

Cake Frosting - A small offset spatula makes it really easy, but you can use a butter knife too. I had fun piping the stars. Totally optional, but looks so patriotic. 🇺🇸 Use a large piping bag and 1M tip to create the stars. I used regular food coloring, just mix until it's a dark enough shade. Red took the whole little bottle. You can also use cool whip cream or a cheese frosting, but those will not hold up on the cake in hot weather or at an outdoor party. This is a popular "bakery-style" cake frosting that is soooo fluffy and not too sweet.

Fresh Berries - I chose to use fresh fruit and love the look of blueberries and raspberries 🫐❤️. But you could slice strawberries for the red stripes. You could also use colored sugar or sprinkles for the stripes or even colored candy.

Marbled Cake FAQ

The cake will hold well overnight in the refrigerator for 1 day, and possibly 2 days if your berries are really fresh.

I would decorate the cake either the day of your party or the night before. I have also had guests decorate it during the party which was SO much fun, they still talk about it.

It is so fun to slice into the corner of the cake and surprise your guests...

More July 4th Desserts

These recipes are a great way to show your patriotism for July 4th, Memorial day, or as a summer dessert for your cookout or picnic.

I have a collection of over 100+ July 4th Desserts with treats from my food blogger friends plus a few of mine, with something for everyone! Make a fabulous Patriotic Ice Cream Cake or these Patriotic Cookies. Bake a patriotic flag-shaped pie like this Grill Baked Blueberry Pie (yes you can bake in your grill!) or a sheet pan American Flag Pie that serves a big crowd. Happy July 4th 🇺🇸, you can also get over 100+ July 4th Recipes and ideas for your party...