Ingredients:

  • 1 box (15.25 oz / 432g) White Cake Mix
  • 1 cup (240ml) Water
  • 3 large eggs
  • 1/3 cup (75ml) Vegetable oil
  • 1/2 cup (120ml) Low-fat buttermilk
  • 8 oz (225g) Low-fat cream cheese, softened
  • 1/4 cup (55g) Unsalted butter, softened
  • 2 cups (240g) Powdered sugar
  • 1 tsp (5ml) Pure vanilla extract
  • 2 tbsp (30ml) Heavy cream
  • 1 pint (250g) Fresh blueberries, rinsed and dried
  • 1 pint (250g) Fresh raspberries, rinsed and dried

Instructions:

  1. Preheat oven to 350°F (175°C) and grease a 9x13 inch baking pan.
  2. Combine the cake mix, water, eggs, oil, and buttermilk in a bowl and beat on medium speed until the batter is smooth.
  3. Pour batter into the pan and bake for 30-35 minutes, or until a toothpick inserted in the center comes out clean.
  4. Allow the cake to cool completely in the pan for at least 1 hour.
  5. Beat softened cream cheese and butter together until velvety and pale.
  6. Gradually add powdered sugar and vanilla extract, mixing on low until incorporated.
  7. Whip in the heavy cream on high speed until the frosting holds stiff peaks.
  8. Spread an even layer of frosting across the cooled cake using an offset spatula.
  9. Arrange blueberries in a rectangular block in the top-left corner to create the Union.
  10. Place rows of raspberries horizontally across the remaining frosting to create the red stripes.
  11. Press the berries gently into the frosting to secure them and ensure clean lines.