Stir flour, baking powder and salt together. Cream shortening; gradually add sugar, beating between additions. Add egg yolks and beat until fluffy. Add dry ingredients, alternately with milk, blending well after each addition. Stir in vanilla. Beat egg whites until stiff but not dry; fold into batter. Pour into two greased and floured or lined 8" layer cake pans. Bake in a moderate oven (350F) 25 to 30 minutes or until done. Frost as desired. Posted to FOODWINE Digest 29 Jan 97 by Rod Grant on Jan 30, 1997.