RESERVE 1/3 cup cherry pie filling for garnish, set aside. Stir boiling water into dry gelatin mix in large bowl at least 2 min. until completely dissolved. Stir in cold water and remaining cherry pie filling. Refrigerate 45 min. or until slightly thickened (consistency of unbeaten egg whites).
PLACE cake cubes in 3-qt. serving bowl. Spoon gelatin mixture over cake. Refrigerate 45 min. or until set but not firm (should stick to finger when touched).
POUR milk into large bowl. Add dry pudding mixes. Beat with wire whisk 2 min. Gently stir in 2 cups of the whipped topping. Spoon over gelatin mixture in bowl. Refrigerate 2 hours or until set. Top with remaining whipped topping and reserved cherry pie filling. Store leftover dessert in refrigerator.