Red Velvet Cake Mary Berry Recipe : 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. Posted by busiwa Monday, December 28, 2020