Preparation / Directions:
Preheat oven to 350 degrees. Prepare two 9" round cake pans with cooking spray and flour; set aside.
To prepare batter, combine cake mix and baking powder in a mixing bowl.
In another mixing bowl, combine water, egg whites, oil, and vanilla extract. Mix dry ingredients with wet ingredients just until moistened. Bake for 25 minutes or until golden brown.
Place cake layers, top sides up, in two clean cake pans. Pierce cake with large fork at 1/2" intervals.
To prepare filling, stir 1 cup of the boiling water into each flavor of gelatin powder in separate bowls 2 minutes or until dissolved. Carefully pour red gelatin over 1 cake layer and lime gelatin over second cake layer. Refrigerate 3 hours.
Dip 1 cake pan in warm water 10 seconds; unmold onto serving plate. Spread with 1 cup of the whipped topping. Unmold second cake layer; carefully place on first layer. Frost top and sides of cake with remaining topping. Refrigerate 1 hour or until ready to serve.