Flag Cake

Total Time

Prep: 1-1/2 hours + chilling Bake: 35 min. + cooling

Makes

15 servings

Updated: Sep. 14, 2023
This patriotic-themed flag cake makes a stunningly delicious centerpiece on any summer celebration table. To honor our troops, pass it along to all your family and friends! —Taste of Home Test Kitchen
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Ingredients

  • 1 package French vanilla cake mix (regular size)
  • 1 cup buttermilk
  • 1/3 cup canola oil
  • 4 large eggs
  • FILLING:
  • 1 package (3 ounces) berry blue gelatin
  • 1-1/2 cups boiling water, divided
  • 1 cup cold water, divided
  • Ice cubes
  • 1 package (3 ounces) strawberry gelatin
  • 2/3 cup finely chopped fresh strawberries
  • 1/4 cup fresh blueberries
  • FROSTING:
  • 3/4 cup butter, softened
  • 2 cups confectioners' sugar
  • 1 tablespoon 2% milk
  • 1 jar (7 ounces) marshmallow creme

Directions

  1. Preheat oven to 350°. Line a 13x9-in. baking pan with parchment paper and grease the paper; set aside. In a large bowl, combine first 4 ingredients; beat on low speed 30 seconds. Beat on medium 2 minutes. Pour into prepared pan.
  2. Bake 35-40 minutes or until a toothpick inserted in the center comes out clean. Cool 10 minutes before removing from pan to a wire rack to cool completely.
  3. Transfer cake to a covered cake board. Using a small knife, cut out a 5x4-in. rectangle (1/2 in. deep) in the top left corner of cake, leaving a 1/2-in. border along edges of cake. For red stripes, cut out 3/4-in. wide rows (1/2 in. deep), leaving a 1/2-in. border between stripes and around edges of cake. Using a fork, carefully remove cut-out cake pieces.
  4. In a small bowl, dissolve berry blue gelatin in 3/4 cup boiling water. Pour 1/2 cup cold water into a 2-cup measuring cup; add enough ice cubes to measure 1-1/4 cups. Stir into gelatin until slightly thickened. Scoop out and discard any remaining ice cubes. Repeat, making strawberry gelatin.
  5. In a small bowl, combine strawberries and 1 cup strawberry gelatin. In another bowl, combine blueberries and 1 cup blue gelatin. Refrigerate 20 minutes or just until soft-set. (Save remaining gelatin for another use.)
  6. Stir gelatin mixtures. Slowly pour blueberry mixture into rectangle; spoon strawberry mixture into stripes.
  7. In a large bowl, beat butter until fluffy; beat in confectioners' sugar and milk until smooth. Add marshmallow creme; beat well until light and fluffy. Spread 1 cup over sides and top edge of cake. Refrigerate remaining frosting 20 minutes.
  8. Cut a small hole in the corner of a pastry bag; insert a large star tip. Fill the bag with remaining frosting. Pipe frosting in between rows of strawberry gelatin and around edges of cake. Refrigerate 1-2 hours or until gelatin is set.
Flag Cake Tips

How else can you decorate a flag cake?

While the gelatin on top gives this cake a gorgeous color and shine, it does require a bit more work and set-up time. Instead, you could begin with a plain white frosted sheet cake and work with fresh fruit to make the flag. Lay out halved strawberries in seven red stripes, and pack fresh blueberries into the top left corner. Now that’s easy! Pull more inspiration from other patriotic dessert recipes.

Can you make flag cake in advance?

Yes. You can make the flag cake up to a day in advance and store it, covered (if possible) in the refrigerator. If you have a container large enough to invert over your flag cake, this is the best way to store the cake and preserve its pretty look. Otherwise, stick toothpicks in inconspicuous areas to help you drape food wrap over the cake without marring the decorated finish. If you plan to store the cake overnight, you’ll need to keep the cake covered to prevent it from absorbing any refrigerator odors. You could ask your grocery’s bakery department to sell you a cake box for storage, or keep it in a refrigerator that doesn’t contain other foods.

How long will leftover flag cake last?

The cake will keep 2 to 3 days, covered, in the refrigerator. But it will look its prettiest on the day it's made! Fill up your dessert table with other red, white and blue desserts to make a patriotic statement.

Christine Rukavena, Taste of Home Senior Book Editor

Nutrition Facts

1 piece: 438 calories, 18g fat (8g saturated fat), 81mg cholesterol, 363mg sodium, 67g carbohydrate (51g sugars, 0 fiber), 4g protein.