Line a square 9x9 inch baking dish with parchment paper.
On the stove, melt a stick of butter on medium low heat. You want to make sure you keep the butter moving with a rubber spatula until the butter browns. This prevents it from burning.
Once the butter has browned, add in the peanut butter and cook until melted. Add in the marshmallows and continue to cook until melted.
Add in the rice krispie cereal and mix until all of the pieces are covered in the peanut butter marshmallow mixture.
Spread the rice krispies evenly in the baking dish.
Melt the chocolate chips in the microwave. Microwave for 30 seconds and mix. Then microwave 10 seconds at a time, mixing after every ten seconds until melted. Spread the chocolate on top of the rice krispie treats.
Top with chopped up Reese's.
Chill in the fridge for 30 minutes. Remove from the fridge, cut and serve.