Ingredients

3 tablespoons unsalted butter, plus more softened for pan 

1 10-ounce bag mini marshmallows 

1 recipe mix-ins (see below) 

5 cups chocolate puffed rice cereal, such as Cocoa Krispies 

1 cup cocktail peanuts, roughly chopped 

1/2 cup chopped semisweet chocolate 

5 cups puffed oat cereal, such as Puffins 

1/2 cup dried cherries or cranberries 

1/2 cup chopped toasted pecans 

1/2 cup toasted pepitas 

5 cups flaked corn cereal, such as Corn Flakes 

1/2 cup chopped dried tropical fruit, such as mango and/or pineapple 

1/2 cup toasted coconut flakes 

1/2 cup chopped macadamia nuts 

5 cups whole-grain oat cereal, such as Cheerios 

3/4 cup chopped freeze-dried raspberries 

3/4 cup chopped white chocolate 

Preparation

Grease a 9-inch square baking pan with softened butter. Melt 3 tablespoons butter in a large pot over medium heat. Add marshmallows; cook, stirring, until melted. Remove from heat.

Stir in cereal and chosen mix-ins to combine. Press into prepared pan; let stand until firm, about 1 hour. Cut into squares and serve, or store in an airtight container at room temperature up to 3 days.