Arrange nine cracker squares onto bottom of 13" x 9" pan, cutting squares to fit, if necessary. In a mixing bowl, combine milk and pudding mixes. Mix well. Fold in whipped topping. Spread half the pudding mixture over squares in pan. Place nine more squares over pudding mixture. Top with remaining pudding mixture and squares. Remove top and foil from frosting container. Microwave frosting in container on high one minute, or until pourable. Spread evenly over cracker squares. Refrigerate four hours or overnight