STIR boiling water into gelatin in medium bowl at least 2 minutes until completely dissolved. Stir in cold water. Pour into 8-inch square pan. Refrigerate 4 hours or until firm.
DIP pan in warm water about 15 seconds. Cut gelatin into cubes, using sharp knife which has been dipped in hot water. Lift cubes from pan with spatula.
SPOON about 1/3 cup of the whipped topping into each of 4 dessert dishes. Using back of spoon, make depression in center; spread topping up sides of dishes. Spoon gelatin cubes into dishes.
REFRIGERATE until ready to serve. Store leftover dessert in refrigerator.