Grease a 9x9 inch baking pan with butter or cooking spray so you end up with thick, even squares. Line your pan with parchment paper for easy removal if desired.
Add cereal and 1 cup of peanut butter candies to a large mixing bowl. Stir until blended.
Add butter and marshmallows to a saucepan, and heat over low-medium heat until melted, stirring often.
Quickly mix in peanut butter, then pour over cereal mixture.
Pour mixture into prepared pan, and spread evenly. How do you press them into the pan without sticking? grease a spatula or your hands with butter or cooking spray or use wax or parchment paper to press the mixture into the pan without it sticking to your fingers.
Place peanut butter cups on top in rows of 3, then press down firmly. Top pan with remaining candies, then press down firmly on those too.
Allow to set for minimum 2 hours inside your fridge. Then cut into 9 equal pieces and serve.
Enjoy!