Step 1: Prepare Your Pan - Start by greasing your 9x13-inch baking pan with cooking spray.
Step 2: Melt the Butter and Marshmallows - In a large saucepan over medium heat, melt the butter and add 12 ounces of miniature marshmallows, stirring until smooth.
Step 3: Mix in the Cocoa Powder - Add the cocoa powder to the melted marshmallow mixture and stir until combined.
Step 4: Combine with Cereal - Gently fold in the Cocoa Krispies cereal until fully coated.
Step 5: Add Chocolate Chips - Stir in the remaining 4 ounces of miniature marshmallows and chocolate chips.
Step 6: Transfer to the Pan - Pour the mixture into the prepared baking pan and press evenly with a spatula.
Step 7: Let It Set - Allow the treats to cool for at least 30 minutes at room temperature.
Step 8: Cut and Serve - Once set, cut into squares and serve.
