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.

BEAT 1/2 cup (1 stick) softened butter and 1 tub (250 g) Philadelphia Cream Cheese in large bowl with electric mixer on medium speed until well blended.

GRADUALLY add 4 cups icing sugar and 4-1/2 tsp. lemon juice, beating until light and fluffy after each addition.