STIR boiling water into dry gelatin mix in large bowl at least 2 min. until completely dissolved. Stir in cold water. Refrigerate about 1-1/4 hours or until slightly thickened (consistency of unbeaten egg whites). Reserve 1-1/2 cups of the gelatin at room temperature.
STIR cherries into remaining gelatin. Spoon into 6-cup mold sprayed with cooking spray. Refrigerate 15 min. or until set but not firm (gelatin should stick to finger when touched and should mound). Add whipped topping to reserved 1-1/2 cups gelatin; stir with wire whisk until well blended. Spoon over gelatin layer in mold.
REFRIGERATE 4 hours or until firm. Unmold. Store leftover dessert in refrigerator.