Flag Cake

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.