Prepare cake mix according to instructions in a 9"by 13" pan. Let cool to room temp. When cool poke holes with a wooden spoon into cake. Drain canned pineapple juice from the crushed pineapple over cake and then add the drained pineapple on the top. Prepare pudding according to box instructions, let pudding set up. When set fold in unfrozen Cool-Whip in with the pudding. Spread the Cool-Whip and pudding over the cake. Cover loosely and refrigerate until ready to serve.