PLACE cake layers, top sides up, in 2 clean 9-inch round pans. Pierce cakes with large fork at 1/2-inch intervals.
ADD boiling water to gelatin mixes in small bowl; stir 2 min. until completely dissolved. Pour over cake layers in pans. Refrigerate 3 hours.
DIP bottoms of cake pans in warm water 10 sec.; unmold. Fill and frost with COOL WHIP. Refrigerate 1 hour.
DECORATE with remaining ingredients as desired. Add birthday cake sparklers for the torches.