Grease and flour a 10-inch fluted tube pan; set aside. In a large bowl, beat cake mix, water, cooking oil, and egg whites with an electric mixer on low speed until moistened. Beat the mixture for 2 minutes on high speed. Stir in the lemon peel. Reserve 2 cups of the batter.
In a small bowl, beat egg yolks on high speed for 2 minutes. Add reserved batter and lemon juice; beat until mixture is combined.
Layer batters alternately in prepared pan, beginning and ending with yolkless batter. Swirl lightly to marble. Bake in a 350 degree F oven for 45 minutes or until wooden pick inserted near center comes out clean. Cool in pan on a wire rack for 15 minutes. Remove from pan and cool completely.
To assemble cake, cut cake horizontally into three layers. Spread Creamy Lemon Frosting between layers. Frost entire cake with remaining frosting. Makes 12 servings.
In a large bowl, beat powdered sugar and cream cheese until smooth. Fold in whipped dessert topping. In a small bowl, beat pudding mix and milk for 2 minutes with an electric mixer on low speed; stir in lemon peel. Fold the pudding into the cream cheese mixture.