Prepare puddings as directed on packages. Mix all 3 prepared puddings and Cool Whip in a large mixing bowl until completely blended.
Layer the bottom of a 9 x 13 baking dish with graham crackers. Layer some of the pudding and Cool Whip mixture on top of the graham crackers. Put another layer of graham crackers, then another layer of the pudding mixture. Again one more layer of graham crackers.
Heat all the chocolate frosting in the microwave for about 15 seconds. Top the cake with the frosting. Spread evenly. Refrigerate overnight. The next day it is ready to enjoy.