-------------------------------LEMON FILLING------------------------------3/4 c Sugar 1 pk Unflavored gelatin ds Salt 3/4 c Cold water 1 ts Lemon peel; finely shredded 3 tb Lemon juice Yellow food coloring; optional 1 c Whipping cream ----------------------------------GARNISH---------------------------------Powdered sugar Lemon slices; quartered, optional In a very large mixing bowl, bring egg whites to room temperature. Meanwhile sift powdered sugar and flour together 3 times. Set flour mixture aside. Add cream of tartar and vanilla to egg whites. Beat till soft peaks form. Gradually add the sugar, 2 tablespoon at a time until soft peaks form. Sift about 1/4th of the flour mixture over the egg white mixture, then gently fold in. Repeat sifting and filding in the remaining flour mixture, using 1/4th of it each time. Gently fold in lemon peel. Gently cut through cake batter with a knife or metal spatula. Bake on lowest rack in a 350~ oven for 40-45 minutes or till top springs back when lgihtly touched. Immediately invert cake in pan. Cool completely. Using a narrow metal spatual loosen sides of cake from pan. Remove cake from pan. Using a serrated or very sharp knife, cut off the top 1-inch of the cake; set aside. With the knife held parallel to the side of the cake, cut around the hole in the cente rof the cake, leaving a 1-inch thickness of cake around the hole, then cut around inside the outer edge of the cake, leaving the outer cake wall 1-inch thick. Using a spoon remove center of cake, leaving 1-inch thick base. Place the hollowed out cake on a serving plate. Spoon filling into the hollowed out section. Replace the top of the cake. Cover and chill for 4-24 hours. Before serving, sift powdered sugar over the cake; if desired, garnish with lemon slices. Lemon Cake Filling. In a saucepan, stir together sugar, gelatin and salt. Gradually stir in cold water. Stir in lemon peel and lemon juice. Heat and stir just till gelatin dissolves. If desired, stir in a few drops yellow food coloring. Cool lemon gelatin mixture in a bath of ice water, stirring constantly for 5-8 minutes or till mixture is the consistency of corn syrup. Remove lemon-gelatin mixture from ice water; set aside. In a medium bowl beat 1 cup whipping crem till soft peaks form. Fold 1/4th of the whipped cream into the lemon gelatin mixture back into the remaining whipped cream. Chill 5 minutes or till the mixture mounds when spooned. Makes 3 cups. -----