What's more fun: pulling these buttery, supermallowy treats apart of eating them?
Line a 9-by-13-inch pan with foil and spray with cooking spray. In a large pot, melt the butter over high heat. Add the bag of marshmallows and 1/2 tsp. salt and, using a silicone spatula, stir until smooth. Remove from heat. Add the cereal and mix until evenly coated. Mix in the remaining 2 cups marshmallows, stirring just until incorporated but not melted. Transfer the cereal to the prepared pan. Spray a clean spatula with cooking spray; pat the cereal into an even layer. Let cool for 2 hours. Cut into squares.