Cream butter and sugar together until well mixed. Add vanilla. Add baking powder and salt to the flour; sift together three times. Beat egg whites until stiff. Add flour to creamed mixture alternately with the milk, beginning and ending with flour. Fold in egg whites. Pour into two 8 inch layer pans that have been greased and lined with waxed paper. Bake at 375 degrees until done. Frost when cake has cooled. To make frosting: Beat egg yolks slightly; add sugar and butter. Put into saucepan; cook over medium heat stirring constantly. Let boil for about 5 minutes and the mixture has slightly thickened. Remove from the heat; add all the remaining ingredients. Spread on cool cake. From . Downloaded from G Internet, G Internet.