- Make the Pudding Mixture: In a medium bowl, mix together the instant vanilla pudding mix, milk, and whipped topping. Stir until everything is well combined and smooth.
- Layer the Cake: In a 9×13-inch baking dish, arrange a single layer of graham cracker squares on the bottom, breaking them up as needed to cover the dish completely.
- Add Pudding & Repeat: Spread half of the pudding mixture evenly on top of the crackers. Add a second layer of graham crackers, then spread the remaining pudding mixture on top. Finish with a third and final layer of graham crackers.
- Chill: Cover the dish with plastic wrap and place it in the fridge for at least 30 minutes to an hour to allow the pudding to set.
- Add Frosting: Once ready to finish, microwave the tub of chocolate frosting for about 15 seconds to soften it (be sure to remove the lid and foil seal first). Stir the frosting until it’s easily spreadable. Remove the plastic wrap from the chilled cake and evenly spread the chocolate frosting over the top layer of graham crackers.
- Chill Overnight: Cover the dish with plastic wrap again and return it to the fridge. Let it chill overnight to allow the graham crackers to fully soften.
- Serve: When ready, slice the cake into squares and serve cold.
