PLACE cake layers, top-sides up, in two clean 9-inch round cake pans. Pierce cakes with large fork at 1/2-inch intervals.
STIR boiling water into dry jelly powder in medium bowl at least 2 min. until completely dissolved. Carefully pour evenly over cake layers. Refrigerate 3 hours.
POUR milk into large bowl. Add dry pudding mix. Beat with whisk 2 min. or until well blended. Gently stir in whipped topping; set aside. Dip one cake pan in warm water 10 sec.; unmold onto serving plate. Spread with about 1 cup of the pudding mixture. Unmold second cake layer; carefully place on first cake layer. Frost top and side of cake with remaining pudding mixture. Refrigerate at least 1 hour before serving. Store leftover cake in refrigerator.