Sift flour, baking powder & salt. Cream shortening. Slowly beat in sugar. Add egg yolds & vanilla. Add cocoa, then flour mixture alternately with milk. Fold in stiffly beaten egg whites. Pour in 2 greased 9" layer cake tins. Bake 25 minutes in 375~ oven. FROSTING:Combine 2 egg whites, unbeaten with 1 1/2 cups sugar, finely sifted. Add 5 tbsps. cold water, a few rains salt and 1/2 tsp. Cream of Tarter in top of double boiler. Stir until sugar is dissolved. Place over briskly boiling water. Beat with egg beater until stiff enough to stand in peaks, about 6-10 minutes. Add 1 tsp. vanilla and beat until thick enough to spread while frosting is cooling. Keep sides of double boiler scraped down with spatula. ----