In a large microwave-safe bowl, melt the butter in 30-second increments until it's fully melted and smooth.
Stir in the miniature marshmallows until they are coated with the melted butter.
Add the semi-sweet chocolate chips to the mixture. Microwave in 15-second intervals, stirring each time
Gently fold in the 6 cups of Cookie Crisp cereal until they are evenly coated with the chocolate marshmallow mixture.
Spray a 9x13-inch baking pan with cooking spray. Transfer the mixture into the pan and press it down firmly with a spatula or your hands.
Allow the Chocolate Rice Krispie Treats to cool and set for at least 30 minutes. You can speed up the process by placing them in the refrigerator.
Once they are set, cut your treats into squares or bars. Drizzle with white chocolate if desired. Now, savor the delicious combination of chocolate and Cookie Crisp cereal!