Step #1
In a large bowl, mix pudding mix & 3 c milk; mix well.
Step #2 Fold in whipped topping & beat with mixer for 2 mins.
Step #3 In a buttered 9x13 inch baking dish, spread a layer of graham crackers on the bottom of the dish.
Step #4 Spread 1/2 of the pudding mixture over crackers, then top this with graham crackers.
Step #5 Spread remaining pudding over crackers; top second pudding layer with another layer of crackers.
Step #6 To make topping: In a medium saucepan over medium-high heat, mix 1/4 c milk, cocoa & sugar & allow to boil for 1 min; remove this from heat & add butter & vanilla.
Step #7 Mix well & cool.
Step #8 Pour sauce over graham cracker layer & put in the fridge until set; serve.