1 Preheat oven to 350 degrees F (175 degrees C), Grease and flour one 9 inch round and one 9×13 inch pan.
2 In a very large bowl stir together flour, sugar, baking powder, soda, and salt.
3 Add milk, 1 cup shortening, 1/2 cup champagne, vanilla, and, if desired, red food coloring. Beat on low to medium speed about 30 seconds or just till combined, scraping bowl constantly. Beat on medium speed 2 minutes.
4 Add unbeaten egg whites and beat for 2 minutes (Batter may appear slightly curdled).
5 Spread 2 3/4 cups batter in 9inch round pan and remaining batter in 9×13 inch pan. Bake at 350 degrees F (175 degrees C) for 30 to 35 minutes for round cake and 40 to 45 minutes for rectangular cake or until cake tests done. Cool cakes in pans on racks for 10 minutes, then remove from pans and cool completely.
6 To make the frosting: In a bowl beat 3/4 cup shortening and butter until combined. Beat in 1 tablespoon champagne. Beat in sifted powdered sugar and a few drops red food coloring. If necessary, beat in additional champagne to make frosting spreading consistency. Makes 3-3/4 cups.
7 Using cardboard circle patterns of 4 and 6 inches, cut one 4-inch and one 6-inch cake layer from the 9×13 inch cake. If desired, drizzle 3 tablespoons of champagne over the top of each round cake layer. Place the 9-inch cake layer on a serving plate; frost sides and top. Lining up the backs of the layers, place the 6-inch cake on top of the 9-inch cake. Frost sides and top. Repeat with remaining 4-inch cake. If desired, tint any remaining frosting and decorate with tinted frosting and flowers. Serves 24.