Mix together pudding and milk.
Fold in whipped topping.
Spray a 9x13 inch pan with non-stick cooking spray.
Line bottom of pan with whole graham crackers.
Put half of pudding mixture on top of crackers and spread evenly.
Place another row of graham crackers evenly on top of pudding mixture, completely covering the pudding.
Put the remainder of the pudding mixture on and spread evenly.
Cover the pudding with more graham crackers, making sure there are no spaces in between the crackers.
Put frosting in microwave for 30 seconds to soften.
With a spatula, spread frosting on top of crackers.
Refrigerate for 1 hour until frosting hardens.
Cover with plastic wrap and keep refrigerate overnight.
This will soften the crackers.
Cut in squares and serve.