Gather together your equipment and ingredients so you have everything ready to go.
Take some butter or some non-stick cooking spray and grease up your spatula and pan.
Melt butter and marshmallows in microwave by adding 4 tbs of butter and 16 oz of marshmallows to bowl and heating in 30 second increments and stirring in between each heating.
Once marshmallows and butter are melted and combined, stop heating and slowly add 6 cups of rice krispies cereal.
Thoroughly fold cereal into marshmallows.
Once cereal and marshmallows are well combined, make sure marshmallows are no longer pipping hot, add 1 cup of mini marshmallows and fold in. Note: you do NOT want the mini marshmallows to melt.
Take your spatula and transfer your mixture into your greased pan.
Gently use the spatula to push the mixure into the pan so that it is the same thickness across the pan.
Set pan aside to cool for 30 minutes.
Use a grease knife and cut treats into even squares.