01 -
Preheat the oven to 350°F (175°C). Grease and line a 13x18 inch half-sheet pan with parchment paper for easy removal and even baking.
02 -
In a large mixing bowl, sift together the flour, granulated sugar, baking soda, cocoa powder, and salt. Mix thoroughly to ensure even distribution.
03 -
In a separate bowl, whisk the vegetable oil, buttermilk, room-temperature eggs, red food coloring, white vinegar, and vanilla extract until smooth and fully incorporated.
04 -
Gradually add the wet ingredients to the dry mixture, gently folding until just combined to maintain tenderness.
05 -
Pour the batter evenly into the prepared pan, smoothing the surface with an offset spatula. Bake for 20 to 25 minutes until a toothpick inserted in the center comes out clean and the cake springs back when pressed lightly.
06 -
Allow the cake to cool in the pan on a rack for 15 to 20 minutes. Lift using the parchment paper and cool completely before frosting to avoid melting.
07 -
Beat softened cream cheese and butter until fluffy. Gradually incorporate sifted powdered sugar, vanilla extract, and salt. Add 1 to 2 tablespoons heavy cream to achieve a smooth, spreadable consistency.
08 -
Spread the frosting evenly over the cooled cake. Arrange fresh raspberries and blueberries atop, distributing them evenly for an attractive finish.