2 cups vanilla frosting (store-bought or homemade)
1 pint fresh blueberries, rinsed and patted dry
1 lb fresh strawberries, hulled and sliced
Instructions
Step 1: Preheat and Prep: Preheat your oven to 350°F (175°C). Grease and flour a 13×9-inch baking pan, or spray it thoroughly with non-stick cooking spray to ensure the cake releases easily after baking.
Step 2: Mix the Batter: In a large mixing bowl, combine the cake mix, water, vegetable oil, eggs, and vanilla extract. Beat with an electric mixer on medium speed for about two minutes until the batter is smooth and well-combined.
Step 3: Bake the Cake: Pour the batter into the prepared baking pan and spread it evenly. Bake for 25 to 30 minutes, or until a toothpick inserted into the center comes out clean. The top should be lightly golden brown.
Step 4: Cool Completely: Remove the cake from the oven and place the pan on a wire rack. It is vital to let the cake cool completely before frosting. If the cake is even slightly warm, the frosting will melt and the fruit will slide off.
Step 5: Frost the Surface: Once cooled, spread an even layer of vanilla frosting over the entire top of the cake. Use an offset spatula to get a smooth, flat surface which will act as the white background for your flag design.
Step 6: Decorate the Flag: Create the “stars” by placing blueberries in a rectangular pattern in the top-left corner of the cake. To create the “stripes,” arrange sliced strawberries in horizontal rows across the rest of the cake, leaving white frosting visible between the rows of red fruit.