I've posted something like this before... The only difference is these are made with Reece's cups not Oreos but you can do your favorite. They are also made into cups/squared. They are easier because you don't have to cut through the dessert.
Peanut Butter Pudding... bursting with milk chocolate chips, peanut butter chips, and Reese's Pieces. I did not have reeses pieces so I used M's and I did not have pb chips so I used butterscotch chips. The kids still loved them!