In a large saucepan set over low heat, melt the butter, stirring continuously.
3 tablespoons unsalted butter
Once melted, add in the marshmallows.
4 cups miniature marshmallows
Continue stirring until they have completely melted with the butter. Remove from stovetop.
Pour in the Rice Krispies and stir until they are evenly coated with the melted marshmallow mixture.
6 cups Rice Krispies cereal
Add in the chocolate chips and stir to combine with the Krispies mixture. Continue stirring until the chips have completely melted into the cereal and marshmallows.
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.