Crispy Cereal Treats

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.

Ingredient :

Base Recipe:
3 tablespoons unsalted butter, plus more softened for pan
1 10-ounce bag mini marshmallows
1 recipe mix-ins (see below)
Cocoa Nutty:
5 cups chocolate puffed rice cereal, such as Cocoa Krispies
1 cup cocktail peanuts, roughly chopped
½ cup chopped semisweet chocolate
Trail Mix:
5 cups puffed oat cereal, such as Puffins
½ cup dried cherries or cranberries
½ cup chopped toasted pecans
½ cup toasted pepitas
Tropical Breeze:
5 cups flaked corn cereal, such as Corn Flakes
½ cup chopped dried tropical fruit, such as mango and/or pineapple
½ cup toasted coconut flakes
½ cup chopped macadamia nuts
Berries and Cream:
5 cups whole-grain oat cereal, such as Cheerios
¾ cup chopped freeze-dried raspberries
¾ cup chopped white chocolate