Cake
2 1/4 cups sifted cake flour (sifted, then measured)
2 tablespoons unsweetened cocoa powder
1 teaspoon baking powder
1 teaspoon baking soda
1/2 teaspoon salt
1 cup buttermilk
1 tablespoon red food coloring
1 teaspoon distilled white vinegar
1 teaspoon vanilla extract
1 1/2 cups sugar
1/2 cup (1 stick) unsalted butter, room temperature
2 large eggs

Frosting
2 8-ounce packages cream cheese, room temperature
1/2 cup (1 stick) unsalted butter, room temperature
1 tablespoon vanilla extract
2 1/2 cups powdered sugar
3 1/2-pint baskets fresh raspberries
3 1/2-pint baskets fresh blueberries