No-bake chocolate éclair cake

How to Make No-Bake Chocolate Flash Cake:
Preparing the pudding mix: In a medium bowl, combine the vanilla instant pudding mix, milk, and whipped topping. Stir until well combined and smooth.
Cake preparation: In a 23 x 33cm baking dish, arrange a single layer of graham cracker squares at the bottom, breaking them up as needed to completely cover the dish.
Add the pudding mix and repeat: Spread half of the pudding mix evenly over the cookies. Add a second layer of graham crackers and spread the rest of the pudding mix on top. Finish with a third and final layer of graham crackers.
Refrigerate: Cover the dish with plastic wrap and place it in the refrigerator for at least 30 minutes to an hour to allow the pudding to set.
Add the frosting: Once the cake is ready to decorate, microwave the jar of chocolate frosting for about 15 seconds to soften it (remember to remove the lid and foil seal first). Stir the frosting until it’s easy to spread. Remove the cling film from the cooled cake and spread the chocolate frosting evenly over the top layer of graham crackers.
Leave to rest in the fridge overnight: Cover the dish with cling film and return it to the refrigerator. Let sit overnight so that the graham crackers soften completely.
Serving: Once ready, cut the cake into squares and serve cold.