Cream together sugar and shortening until light. Add egg yolks and cream 2 minutes. Add coffee and stir. If using cocoa, stir into coffee. Sift flour, baking powder, salt and soda together and alternate with milk. Add nuts. Beat egg whites until stiff and stir in vanilla. Fold in egg whites. (A small drop of red cake coloring may be added to enhance color.) Divide evenly into 2 (9-inch) cake pans lined with wax paper. Bake at 350° for 20 to 35 minutes. (This makes the 9-inch cake pans pretty full, so to make sure they don't run over, I make a couple of cupcakes.)