Preheat oven to 350°F
Use a stand mixer to combine the butter and sugar.
Mix eggs one at a time.
Add the vanilla.
Mix the flour, cocoa, and salt together.
Place the brownie mix in a 9x13 pan lined with parchment paper. Spread the batter.
Bake for 30 minutes, or until done.
Cool completely
Spread marshmallow cream over the brownies.
Combine peanut butter and chocolate chips in a small saucepan. Heat on low heat. Mix well.
Toss in the cereal until it is all coated.
Spread marshmallow cream.
Let cool in the refrigerator until firm. Then, cut into squares