Mix 2 tablespoons cocoa in 2 ounce red food coloring and set aside. mix 1 and 1/2 cups sugar, 1/2 cup shortening, 2 eggs. Add 1 teaspoon salt, 1 teaspoon vanilla.
To cocoa mix, add 1 cup buttermilk and add this alternately with 2 and 1/2 cups cake flour. Mix 1 and 1/2 teaspoons soda and 1 tablespoon vinegar. Fold in carefully and immediately to above. Bake in two 9 inch cake pans at 350 degrees for 30 minutes.
Frosting: Cook until very thick, 5 tablespoon flour and 1 cup milk. Cool. Cream until fluffy 1 cup butter and 1 cup fine granulated sugar. Add 1 teaspoon vanilla. Mix into cooked paste well, and spread on cool cake.