Sift together the flour, cocoa, baking soda and salt; set aside. Cream the shortening and sugar in a mixing bowl until light and fluffy, using an electric mixer at medium speed. Blend in the corn syrup and egg yolks. Beat in vanilla. Add dry ingredients alternately with coffee to creamed mixture, beating well after each addition.
Beat egg whites in another bowl until stiff peaks form. Fold egg whites into cake batter. Pour batter into a greased 13x9x2 inch baking pan. Bake in preheated 350 degree oven 45 minutes or until cake tests done. Cool in pan on rack.
NOTE: This cake recipe dates from WWII and as you can see, sugar was very precious and in short supply.