A recipe for a flag cake sheet cake that isn't too huge. A moist and delicious vanilla cake with the perfect cream cheese frosting and plenty of fresh summer berries.
Prep. Start by preheating the oven to 350°F and greasing a 10x16-inch rimmed sheet pan with non-stick baking spray.
Beat butter and sugar. In a large mixing bowl, beat the butter and sugar with an electric mixer on medium speed until light and fluffy. Add the eggs one by one, fully incorporating each egg before adding the next one, and stir in the vanilla.
Combine dry ingredients. Combine the flour, cornstarch, salt, baking soda, and baking powder in a separate bowl. Gradually add the dry ingredients to the butter mixture, alternating with the milk, starting and ending with the dry ingredients. Mix on low until everything is just combined. Don't forget to scrape down the sides of the bowl as needed.
Pour into baking sheet. Pour the batter into the pan and smooth the top with a spatula. Bake for 17-19 minutes or until a toothpick comes out clean. Let the cake cool completely in the pan on a wire rack.
Make The Frosting
Mix. Use a clean bowl to beat the butter, cream cheese, and vanilla until it becomes fluffy. Gradually add the powdered sugar, beating until the frosting becomes smooth.
Assemble The Cake
Spread. Spread half the frosting over the cooled cake. Using a toothpick, draw a rectangle for blueberries in the upper left corner.
Add the berries. Fill the upper left square with blueberries. Make a double row of raspberries on top of the cake to the right of the blue square. You will want the bottom of the blue square to line up with the bottom of a raspberry row, so space the rows accordingly. Continue with double rows of raspberries, leaving space in between for white stripes.
Add the remaining frosting. Finally, fill a piping bag fitted with a star tip with the remaining cream cheese frosting. Pipe stars over the blueberries and stripes between the raspberry rows.
Serve. When it's time to serve, you can serve the cake directly from the pan and refrigerate any leftovers.
Notes
Don’t worry if you make a few mistakes laying out the berries or piping on the frosting. The end result will still look like a flag and be beautiful.You can substitute halves of strawberries for the raspberries if you prefer.