Lightly crush the pretzel twists, leaving them very chunky.
Add the marshmallows and butter to a large saucepan over medium heat and cook, stirring constantly, until completely melted, about 5 minutes. Remove from the heat and add the crushed pretzels, cereal, chocolates, doughnuts, peanuts and potato chips. Stir quickly, until the mixture is just combined and an even consistency.
With a spatula, transfer to a 9-by-13-inch casserole dish that has been greased with cooking spray. Spray your hands with a little cooking spray and pat the mixture down until flat and even. Let cool for at least 30 minutes. Cut into squares and serve.