1 box yellow cake mix
1 box lime jello (regular or sugar-free)
1 box lemon jello (regular or sugar-free)
1 large container Cool Whip (regular or fat-free)

Mix cake mix as directed on box; divide mix into 2 round 9-inch cake pans. Mix jello powder (lime in one, lemon in the other).

Bake and let cool. Put Cool Whip on top of bottom layer stack. Place Cool Whip all over the rest of the cake; refrigerate until ready to serve. Very, very good.