Go Back

American Flag Cake

American flag cake made as a patriotic sheet cake with a thick white frosting base and a clean blueberry canton, red strawberry stripes, and white banana or frosting stripes. A full sheet cake design bakes, then cools and assembles for an Independence Day cake look.
Print Recipe Pin Recipe
Prep Time 45 minutes
Cook Time 35 minutes
cooling 1 hour
Total Time 2 hours 20 minutes
Servings: 20 servings
Course: Dessert
Cuisine: American
Calories: 520
Ingredients Equipment Method Notes

Ingredients
  

white cake
  • 2 boxes white cake mix Use the cake-mix instructions for the eggs, water, and oil called for on the box.
buttercream frosting
  • 2 cups unsalted butter Softened to room temperature.
  • 6 cups powdered sugar
  • 2 tsp vanilla extract
  • 4 tbsp heavy cream Add 4–6 tbsp as needed to reach spreadable thickness; start with 4 tbsp.
flag fruit decoration
  • 2 cups fresh blueberries Rinse and pat dry.
  • 2 lb fresh strawberries Hulled and sliced lengthwise for lengthwise stripe rows.
  • 1 banana slices Optional: use for white stripes if you don’t want to pipe frosting stripes.

Equipment

  • 1 sheet pan

Method
 

Bake the sheet cake
  1. Preheat and bake two white cake mixes in a large 12x18 sheet pan or two 9x13 pans joined together according to package directions.
  2. Bake until a toothpick comes out clean, then cool completely before frosting.
Make the white buttercream
  1. Beat softened unsalted butter until fluffy, about 2-3 minutes, then scrape the bowl.
  2. Gradually add powdered sugar while beating, then add vanilla extract.
  3. Beat in heavy cream, 1 tablespoon at a time, until the frosting is smooth and spreadable (typically 4–6 tbsp total).
Frost and decorate as a flag
  1. Frost the entire top of the cooled sheet cake with a thick, even layer of white buttercream.
  2. In the upper left corner, arrange fresh blueberries into a dense rectangle to form the canton.
  3. Create red stripes by arranging sliced fresh strawberries flat across the length of the cake in uniform rows.
  4. Fill the white stripes by piping extra frosting in rows between the strawberry rows or by placing thin banana slices.
Chill and slice
  1. Refrigerate until ready to serve, about 1 hour, so the fruit and frosting set.
  2. Slice into squares and serve chilled.

Notes

Pro tip: slice strawberries consistently (same thickness/lengthwise cut) so the red rows look straight from an overhead view. Store covered in the refrigerator up to 3 days; assembled cake is best within 48 hours for brightest fruit. Freezing is not recommended due to fruit texture. For a lighter option, substitute a portion of the powdered sugar with a stabilized whipped frosting base, keeping enough sugar to hold the stripes.