Peanut Butter Éclair Cake

Create the base layer of crackers - In a 9x13-inch baking dish, arrange one-third of the graham crackers to cover the bottom of the dish. Break up the crackers into smaller pieces as needed to create an even layer.

Make the peanut butter pudding - In a mixing bowl, use a hand mixer to mix together the instant pudding and cold milk. Mix in the peanut butter until smooth, then fold in the whipped topping.

Top the graham crackers - Spread half of the peanut butter pudding mixture over the first graham cracker layer. Add another layer of graham crackers, another layer of pudding, and finish with one final layer of graham crackers. Transfer the éclair cake to the freezer for 15 minutes or the fridge for 30 minutes to chill while you make the chocolate ganache.

Make the ganache - Transfer the chopped chocolate to a heat-safe bowl. In a small saucepan, heat the heavy cream until just boiling. Pour the hot heavy cream over the chopped chocolate and allow the mixture to sit for 3 minutes without stirring. Whisk until smooth.

Chill and set - Immediately after whisking, pour the chocolate ganache over the chilled éclair cake and smooth with a spatula. Sprinkle the top with chopped peanut butter cups, if using. Cover the baking dish and transfer the éclair cake to the fridge to chill for at least 5 hours. To serve, slice with a sharp knife, rinsing or wiping the knife between cuts for cleaner slices. Store any leftover éclair cake covered in the fridge for up to 4 days.