Place cake pieces in a large bowl. In another bowl, whisk milk & pudding mixes for 2 minutes. Let stand for 2 minutes or until soft-set. Stir in ice cream until well mixed. Pour over cake pieces, stir just until combined. Transfer to a 5 quart trifle bowl. Spread with Cool Whip topping & sprinkle with toasted coconut. Cover and refrigerate for at least 30 minutes before serving. Yield - 20 servings.