Pineapple Layer Cake

Makes a 9 inch cake. Cream the butter or margarine with 1 1/2 cups sugar in a large mixing bowl. Sift the flour 4 times with the baking powder. Add the sifted ingredients alternately with the milk to the creamed mixture. Beat the egg whites until they are stiff, but not dry. Fold them into the batter. Pour the batter into three 9 inch round cake pans. Bake in a preheated 350 degrees F (175 degrees C) oven for approximately 30 minutes. Place on wire racks until cool. While the layers are cooling make the filling. Combine the egg yolks, 1/4 cup sugar, corn starch, and pineapple juice in the top of a double boiler. Cook until thick; stir often. Cool, and spread filling on top of two of the layers. Sprinkle nuts and crushed pineapple on top of filling. Place these two layers one on top of the other, and place third layer on the top. Frost with any white frosting.