Prepare a 9x13 pan with parchment paper

Melt butter and marshmallows in a pan over medium heat

Stir until well combined

In a separate bowl measure out cereal

Pour the marshmallow mixture over the cereal and stir until combined

Pour the Rice Krispies into the prepared pan

Do not press!

Gently spread the rice krispy mixture to the corners

Cover and allow it to set or add toppings immediately