In a double boiler, or a medium sized bowl placed over a pan with steaming water, add Nutella, chocolate chips, butterscotch chips, and butter.
Heat and stir until mixture is smooth. Remove from heat.
Add Rice Krispies cereal into bowl and stir well.
Dollop the crunch topping on top of the marshmallows and use a knife to carefully spread, being cautious to not completely smash the marshmallows.
Wait (as long as you can! ;) for chocolate to set before cutting. Serve and enjoy!