We are huge Reese's Peanut Butter Cup fans, at our home. If it has chocolate and peanut butter in it, it won't last long. I think I may even like these Mini Peanut Butter Cup Trifles, more than just eating a plain candy bar.
In a large bowl, whisk milk and pudding mix for about 2 minutes. Let stand 2 minutes or until soft-set. In a 4 transparent cups. layer the cake cubes, pudding, whipped topping and peanut butter cups. Repeat layers.
Keep refrigerated until ready to serve. Top with a Reese's Peanut Butter Cup.
(Depending on the size of your cup, you might need more pudding)