Because can never have too much chocolate.
Mix It Up: Line a 9-by-13-inch pan with foil and spray with cooking spray. In a large pot, melt the butter over high heat. Stir cocoa powder into the melted butter. Add the bag of marshmallows and 1/2 tsp. salt and, using a silicone spatula, stir until smooth. Remove from heat. Add the cereal and mix until evenly coated. Chop up a 4-oz. bar of chocolate. Mix in the remaining 2 cups marshmallows and chocolate, stirring just until incorporated but not melted.
Top It Off: Transfer the cereal to the prepared pan. Spray a clean spatula with cooking spray; pat the cereal into an even layer. Let cool for 2 hours. Cut into squares. Melt chocolate chips. Dip the treats in the chocolate and transfer to a baking sheet lined with wax paper. Sprinkle the treats with flaky sea salt.