Orange Creamsicle Pudding

Dissolve Orange Jell-O in 1 cup boiling water. Fill a 1 cup measuring cup 1/2 full with ice cubes and fill with cold water. Add to Jell-O. Stir until ice is melted and then set aside for 5 minutes. Stir in 1 cup of Mandarin oranges. Save the other half cup for decorating the dessert. With an electric mixer, blend in instant vanilla pudding, beating until well blended. Let stand for 15 minutes. Fold in half the tub of Cool Whip. Spoon into individual serving dishes or one large dish, top with remaining Cool Whip. Decorate with the remaining 1/2 cup mandarin slices. Store, covered, in refrigerator until ready to serve.