Preheat your oven to 350°F (175°C).
In a large mixing bowl, prepare the brownie mix according to the package instructions.
Pour the brownie batter into a greased 9x13-inch baking pan and spread it evenly.
Bake for 20-25 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.
Let the brownies cool in the pan.
In a microwave-safe bowl, combine the creamy peanut butter and marshmallow creme. Microwave for 30 seconds, then stir until smooth.
Spread the peanut butter and marshmallow mixture over the top of the cooled brownie base.
In a separate bowl, combine the Rice Krispie cereal and semi-sweet chocolate chips.
Pour the melted peanut butter mixture over the cereal and chocolate chips, and stir until everything is coated evenly.
Carefully spoon the Krispie mixture over the peanut butter layer, pressing it down gently.
Refrigerate for at least 30 minutes to allow the layers to set.
Cut into squares and enjoy!