No-Bake Chocolate Eclair Dessert

Ingredients:
Filling:
2 (3.5 oz.) boxes vanilla instant pudding
3 c. milk
1 (8 oz.) container Cool Whip
Graham crackers
Topping:
1/3 c. cocoa
1 c. sugar
1/4 c. milk
1 stick (1/2 c.) butter (or margarine)
1 tsp. vanilla
Directions:
For the filling:
Combine pudding mix and milk; beat. Stir in Cool Whip.
Place a layer of graham crackers in the bottom of a 9×13″ dish. Spread 1/2 of the pudding mixture over the graham crackers. Repeat with another layer of graham crackers and pudding; then top with a final layer of graham crackers.
For the topping:
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