The recipe for red velvet cake combines cocoa powder, red food coloring and buttermilk with flour, eggs, butter and sugar. It requires one hour of preparation time and yields one 9-inch, 3-layer cake.
Preheat the oven to 350 degrees Fahrenheit. Coat three 9-inch, round baking pans with butter and sifted cocoa powder. Cream 1/2 cup of softened butter with 1 1/2 cups of sugar. Add 2 eggs, one at a time, and beat to combine completely. Mix 2 teaspoons vanilla into the mixture. In a small bowl, combine 2 tablespoons cocoa powder and 2 tablespoons red food coloring. Add the mixture to the batter.
In a large bowl, mix 2 1/2 cups of sifted flour, 1 teaspoon of salt and 1 teaspoon of baking soda. Add one-half of the dry ingredient mixture to the batter, mixing thoroughly, then add 1/2 cup buttermilk, again mixing thoroughly. Repeat with the remaining one-half of the dry ingredients. Add 1 tablespoon vinegar to 1/2 cup buttermilk, then add the mixture to the batter. Combine completely.
Evenly divide the batter into the cake pans, and bake for 20 to 25 minutes. Transfer the pans from the oven to a wire rack to cool before assembling the cake. Place one cake on a serving platter, and spread 1 cup icing over the top. Place another cake on top of the iced cake. Repeat the process for the third cake, then ice the top and sides of the cake.