Coat a 9 X 13 baking dish with butter or baking spray and set aside.

Spray a large saucepan with cooking spray. Add the butter to the saucepan and melt over low heat.

Once the butter has melted, add the marshmallows and continue to cook over low heat stirring frequently until the marshmallows have melted. Remove from the heat and allow to sit for a minute to cool slightly.

Add the peanut butter and stir until well combined with the melted marshmallows.

Remove from the heat and stir until all of the cereal pieces are coated with the marshmallow mixture.

Place the warm mixture into the prepared baking pan.

Lightly butter hands or spray hands with baking spray and press the cereal mixture into the pan, being careful not to press to hard.

Set aside to cool completely before cutting.

Melted milk chocolate chips can be added to the top of the treats. Allow the chocolate to set back up before cutting, or drizzle with chocolate after cutting.