Stir boiling water into gelatin in large bowl 2 minutes until completely dissolved.

Stir in cold water. Place mandarin oranges into 6 cup mold; spoon 2 cups gelatin mixture into mold over oranges. Refrigerate about 30 minutes or until set but not firm.

Meanwhile, refrigerate remaining gelatin mixture about 30 minutes or until slightly thickened. Stir in 2 cups of the whipped cream with wire whisk until smooth. Pour over gelatin layer in mold.

Refrigerate 4 hours or until firm. Unmold. Garnish with remaining whipped topping.