STIR boiling water into gelatin in medium bowl at least 2 minutes until completely dissolved. Add ice cream; stir until melted.
PLACE 1 wafer in each of 8 small cups. Cover evenly with the gelatin mixture.
REFRIGERATE 30 to 45 minutes or until firm. Top with the whipped topping and remaining 8 wafers just before serving. Store leftover dessert cups in refrigerator.