Instructions

• Line a 9×13-inch pan with parchment paper, leaving an overhang on two sides for easy removal; set the pan aside. Preheat the broiler.
• In a large pot over medium heat add the 1/2 cup (1 stick) salted butter and 1 cup creamy peanut butter. Stir until the butter melts into the peanut butter and the mixture is smooth, then reduce the heat to low.
• Add the 1 bag (10 ounces) mini marshmallows to the pot and stir constantly until fully melted and smooth, about 4–6 minutes. Remove the pot from the heat.
• Stir 5 cups Corn Flakes or Rice Krispies cereal into the melted marshmallow mixture until the cereal is evenly coated.
• Arrange 2 cups regular marshmallows in a single layer on a baking sheet. Place the sheet under the preheated broiler 1–2 minutes, watching very closely, until the marshmallows are toasted to your liking. Remove immediately to avoid burning.
• Immediately add the toasted regular marshmallows to the cereal mixture and gently fold them in so they are distributed but not completely melted.
• Transfer the mixture to the prepared 9×13 pan. Using a spatula or the bottom of a measuring cup, press and pack the mixture firmly and evenly into the pan.
• Melt 20 ounces semi-sweet or dark chocolate until smooth (microwave in 20–30 second bursts stirring between, or melt over a double boiler). Pour the melted chocolate evenly over the packed cereal layer and spread to the edges. Sprinkle flaky sea salt on top, if desired.
• Refrigerate until the chocolate and bars are firm, at least 1–2 hours. Use the parchment overhang to lift the slab from the pan, then cut into bars and serve.