Sift flour, baking soda, baking powder and salt together. Cream shortening; slowly beat in sugar, egg yolks and vanilla extract. Add cocoa and flour mixture alternately with milk. Fold in stiffly beaten egg whites. Pour into 2 greased layer cake tins.
Bake for 25 minutes at 375 degrees F, or use greased 9-inch square tin, baking for 45 minutes at 350 degrees F.
Ice with a Seven Minute Frosting.