Butter a 13 x 9-inch baking dish and set aside. In a medium saucepan, melt the butter. Add in the marshmallows, nutella, and salt and stir until melted and smooth. Fold in the cereal and the pretzels and toss to combine. Press the mixture into the prepared baking dish and set aside.
For the Topping:
Melt the chocolate chips and heavy cream together in a microwave-safe bowl, stirring every 15 seconds until completely melted and smooth. Pour the mixture over the cereal treats and spread out so even. While the chocolate is still warm, top with the crushed pretzels and a sprinkling of coarse sea salt. Allow to set until firm. Slice and serve!
I used the basic recipe for cereal treats that everyone knows and loves but adapted it to include my bonus flavors.