Preheat oven to 350 degrees. Cream butter until soft and bright. Gradually add sugar and continue creaming in order to incorporate as much air as possible.
Combine flour, baking powder, and salt. Sift together 3 times, or stir until blended.
Add flavorings to milk and water. Alternate adding flour and liquid mixtures to butter mixture. Beat well after each addition.
Beat egg whites until stiff but not dry and fold into batter. Blend well but do not beat. Pour into three greased and floured 9 inch layer cake pans and bake for 25 minutes. Cool 5 minutes, then turn onto cake racks and remove pans. Wait until cake is cool to frost with Shiny Chocolate Frosting.