American Flag Sheet Cake

Updated: Aug 3, 2020


For the Cake:

  • 9 tablespoons unsalted butter, at room temperature

  • 1 1/2 cups cane sugar

  • 3 eggs, at room temperature

  • 1 cup sour cream

  • 3/4 teaspoon vanilla extract

  • 1 1/2 cups all-purpose unbleached flour

  • 1/6 cup potato starch

  • 1/2 teaspoon sea salt

  • 1/2 teaspoon baking soda

For the Frosting:

  • 2 sticks unsalted butter

  • 1 cup cream cheese (1 package), at room temperature

  • 1/2 cup confectioner’s sugar, sifted

  • 3/4 teaspoons vanilla extract

For Decorating:

  • 2 half-pints raspberries

  • 2 half-pints blueberries

You can also use blackberries and strawberries if preferred. Feel free to mix and match the berries of your choice to make this design!

Baking supplies:

  • electric mixer or stand mixer with a paddle attachment

  • strainer or flour sifter

  • 9-inch x 13-inch cake pan

  • offset spatula

  • toothpick

  • pastry bag or ziplock bag


For the Cake:

  1. Preheat the oven to 350 degrees F. Line a 9-inch by 13-inch cake pan (or a casserole dish or foil pan) with parchment paper, if you plan on removing the cake from your pan. If not, you can simply coat the bottom and sides with cooking oil/butter.

  2. In a bowl with an electric mixer or stand mixer with a paddle attachment, cream together the butter and sugar on high speed, until it is light and fluffy.

  3. Add the eggs, followed by the sour cream and vanilla. Using medium speed, mix until the batter is smooth. It is okay to stop and scrape down the sides of the bowl when needed.

  4. In a separate bowl, sift together the flour, starch, baking soda, and salt.

  5. Add the flour mixture into the batter bowl while mixing on low speed until it is combined.

  6. Pour the batter into your prepared pan, evenly spreading it with a spatula or spoon. Bake in the center of the oven for 20 to 30 minutes. When the cake passes the toothpick test, it is ready!

  7. Remove from the oven and let it cool to room temperature.

For the Frosting:

  1. In a bowl with an electric mixer or stand mixer with a paddle attachment, combine the butter, cream cheese, powdered sugar, and vanilla until smooth.

For Decorating:

Ensure your cake is cooled and at room temperature before getting started! If needed, put the cake in the fridge for an hour or the freezer for 20 minutes.

  1. Spread 3/4 of your icing onto the top of the cake.

  2. Using a toothpick, outline the flag design.

  3. Fill the upper left corner with blueberries.

  4. Fill in every other stripe with raspberries.

  5. Put the rest of your icing in a pastry bag, or Ziploc bag, and pipe it onto the remaining stripes not filled with raspberries. If you like, you can also add stars on top of the blueberries.

Ta-da! You’ve now got yourself a mighty fine American flag cake. Now all that is left to do is celebrate and eat up!



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Amanda MacGregor and Joseph Centineo

EST. 2013 | New Jersey, United States |