Line a 9×9 inch pan with foil or parchment paper and grease with butter or nonstick cooking spray.
Bring a large pot or stock pot to medium heat and add butter and melt.
Reduce the heat to low heat and add 10 ounce bag of mini marshmallows. Stir until melted, then add vanilla extract.
Remove the pot from heat and stir in the cereal until the marshmallow mixture completely coats the cereal. Stir in the remaining 2 cups of marshmallows until evenly distributed coated.
Add the mixture to the prepared 9×9 inch pan and gently press the mixture into the pan. Make sure you don't press too hard otherwise your treats will be too dense and hard. Let rest for 30-60 minutes and slice into squares. Enjoy!
