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.