Beat butter and shortening at medium speed with an electric mixer about 2 minut es or until creamy. Gradually add sugar, beating 5 to 7 minutes. Combine milk and water. Combine flour, baking powder, and salt; add to creamed mixture alt ernately with milk mixture, beginning and ending with flour mixture. Beat at l ow speed just until blended after each addition. Stir in flavorings.

Beat egg whites at high speed until stiff peaks form; fold into batter. Pour b atter into 4 greased and floured 9-inch round cakepans. Bake at 350� for 20 to 25 minutes or until a wooden pick inserted in center comes out clean. Cool in pans on wire racks 10 minutes; remove from pans, and cool on wire racks.

Combine coconut and lemon juice, tossing gently.

Spread Lemon Filling between layers and on top of cake; spread Lemon-Butter Fro sting on sides. Press coconut mixture into frosting on sides of cake. 1 (4-layer) cake.

Lemon-Butter Frosting: Beat butter at medium speed of an electric mixer until c reamy. Add 1 cup powdered sugar, beating until blended; gradually add milk, be ating until blended after each addition. Beat in lemon rind and vanilla. Grad ually beat in remaining sugar until blended; beat to spreading consistency. Yi eld: about 3 cups.

Lemon Filling: Combine first 3 ingredients in a heavy saucepan; gradually stir in water and lemon juice. Bring to a boil over medium heat, stirring constantl y, 2 to 3 minutes.

Stir about one-fourth of hot mixture into egg yolks; stir into remaining hot mi xture. Cook, stirring constantly, 1 minute or until mixture thickens and boils Make Two Sheet Cakes: The cake batter may be baked in two greased and floured 1 3x 9-inch pans at 350� for 30 to 35 minutes or until a wooden pick inserted in center comes out clean. One recipe of lemon-butter frosting or chocolate glaz e will top both cakes. For the lattice design, you'll need two recipes of lemo n-butter frosting For a variation on the classic lemon cake, substitute this recipe for the lemon frosting. This makes enough glaze for the four-layer cake or the two 13x 9inch cakes.

1 (16-ounce) package semisweet chocolate chips 1 cup whipping cream 1/2 cup but ter, softened Combine chocolate and whipping cream in a large glass bowl. Microwave at Mediu m-High (50% power) 3 1/2 minutes. Remove and whisk or stir until chocolate mel ts and mixture is blended, 1 to 2 minutes. If chocolate isn't melted, microwav e again at 50% power 30 to 60 seconds; stir briskly. Whisk or stir in butter. Set aside 10 to 15 minutes or until mixture has cooled to a spreading consiste ncy.