Ingredients:

  • 360g all-purpose flour
  • 350g granulated sugar
  • 1.5 tsp baking powder
  • 0.5 tsp baking soda
  • 1 tsp fine sea salt
  • 225g unsalted butter, room temperature and cubed
  • 240ml buttermilk, room temperature
  • 3 large eggs, room temperature
  • 2 tsp pure vanilla bean paste
  • 225g mascarpone cheese, chilled
  • 480ml heavy whipping cream, chilled
  • 120g powdered sugar, sifted
  • 1 tsp almond extract
  • 1 pint fresh blueberries
  • 1 lb fresh strawberries, hulled and sliced vertically

Instructions:

  1. Preheat your oven to 350°F (175°C). Grease a 9x13-inch professional grade aluminum cake pan and line the bottom with parchment paper.
  2. In a stand mixer fitted with the paddle attachment, whisk together the flour, granulated sugar, baking powder, baking soda, and salt on low speed for 30 seconds.
  3. Add the cubed, room-temperature butter to the dry ingredients. Mix on low speed until the mixture resembles coarse sand and no large butter chunks remain (reverse-creaming method).
  4. In a separate jug, whisk the buttermilk, eggs, and vanilla bean paste. With the mixer on low, slowly pour the liquid into the flour-butter mixture. Increase to medium and beat for 1 minute to aerate and develop structure.
  5. Pour batter into the prepared pan and smooth the top. Bake for 25 minutes, or until a toothpick inserted in the center comes out clean. Cool completely in the pan before frosting.
  6. To make the frosting, place chilled mascarpone, heavy cream, powdered sugar, and almond extract into a chilled bowl. Use the whisk attachment to beat on medium-high speed until stiff peaks form.
  7. Spread the mascarpone frosting evenly over the cooled cake using an offset spatula.
  8. Arrange blueberries in the top-left corner to represent the stars. Place the sliced strawberries in horizontal rows to represent the stripes of the flag. Serve immediately or chill.