Not only does this dish combine an entire box of brownie mix with marshmallows and rice cereal, but also cooked brownies are folded in to give the dessert some extra decadence.
This recipe from the food blog Cookies and Cups with Shelly Jaronsky is a little more involved, but all you'll need in addition to the brownie mix is mini marshmallows, rice cereal, and butter.
You can either make your own brownie pieces with the rest of the mix or buy some store-bought brownies to fold through the treat.