Prepare the Baking Dish
Preheat the oven to 350 degrees
Line a 9x13-inch baking dish with parchment paper or lightly grease with nonstick cooking spray.
Add 6 tablespoons of butter, the entire bag of marshmallows and 6 cups of rice krispies to your dish.
Place dish in the oven for 20 minutes
Remove from oven, mix well then add 2 more cups of rice krispie cereal and mix.
Use the rubber spatula (or lightly greased hands) to press the mixture evenly into the pan. Be careful not to press too hard, as this can make the treats too dense.
Allow the treats to cool at room temperature for 20–30 minutes before slicing into squares or rectangles.
