In a large bowl, combine the pudding and milk. Whisk until combined.
Gently fold in whipped topping.
Place a single layer of graham crackers in the bottom of a 13x9 baking dish.
Place half of the pudding mixture on top of the graham crackers.
Top with another layer of graham crackers and spread the remaining pudding mixture on top.
Add a final layer of graham crackers on top.
Bring cocoa, milk, and sugar to a full rolling boil; boil about 1 minute, stirring very frequently.
Remove from heat and cool one minute. Add butter and vanilla; stir until butter is melted.
Pour chocolate topping over the top layer of graham crackers.
Refrigerate over night.
Notes
Add Different Crackers: Cinnamon graham crackers, chocolate graham crackers or honey graham crackers.
Short cut tip: Feel free to use a premade chocolate ganache, chocolate glaze or use a store bought chocolate frosting, warm in the microwave to make spreadable.
Variation tip: Sprinkle a few tablespoons of chocolate chips or crumbled candy pieces on the pudding layer for added fun.
Alternate ingredient: Replace the pudding with a pastry cream. You can buy store bought or make your own.
Dietary consideration tip: Low fat milk is a great way to lower the fat and calories in this dish.