In a large saucepan set over low heat, melt the butter, stirring continuously. Once melted, add in the marshmallows and continue stirring until they have completely melted with the butter. Remove from stovetop.
Stir in the Rice Krispies and stir until they are evenly coated with the melted marshmallow and butter. Stir in the chocolate chips and stir to combine with the Krispie mixture. Continue stirring until the chips have completely melted into the cereal and marshmallows.
6 cups Rice Krispies cereal, 1 cup semisweet chocolate chips
Line a 9x13-inch baking pan with wax paper, or coat with butter. Use a lightly sprayed rubber spatula, and pour the Krispie mixture into the pan. Use the back of a spatula or a piece of wax paper over the treats and press into the pan. Sprinkle more chocolate chips on top if desired. Allow the treats to cool and the marshmallows to set, about 30 minutes. Cut into squares and serve.
Marshmallows: 1 7-ounce tub of marshmallow creme can be substituted for the mini marshmallows.
When you add the marshmallows to the butter, stir continuously! This will prevent the marshmallows from clumping together or getting stuck to the pan and burning.
Want to get more creative? Instead of placing more chocolate chips on top of the bars, try using M&M's or chocolate shavings!
If you're using wax paper to prepare your baking pan, consider letting about an inch of the paper hang out of the sides of the pan. That way, when the treats are ready to be cut into squares, you can lift them out of the pan and not have to worry about leaving knife marks.
Storage: Store chocolate Rice Krispie treats in an airtight container at room temperature for up to 1 week, in the refrigerator for up to 2 weeks, or in the freezer for up to 3 months.