Preheat your oven to 350 degrees Fahrenheit.
Spread the melted peanut butter evenly in the bottom of an 8-inch cast-iron skillet.
Place the peanut butter cups on top, then add a layer of marshmallows. Stick the chocolate squares upright between the marshmallows.
Bake for 8-10 minutes or until the marshmallows turn golden.
Serve it up warm with your favorite cookies, graham crackers, or anything else you like! Get ready for a delicious treat that's quick, easy, and perfect for any time of the year.