Adapted from Serious Eats
~from Savoring Time in the Kitchen
Either a 9x13-inch or two 8x8 pans will work for this recipe, depending one how thick you like them.
Serves 9
6 tablespoons unsalted butter, plus extra for greasing pan
1/8 teaspoon salt
10 1/2 ounces (one bag, about 5 cups) marshmallows
7 ounces bittersweet chocolate, finely chopped (I used Ghiradelli 60% Bittersweet)
2 tablespoons cocoa powder
1 teaspoon vanilla extract
7 cups puffed rice cereal (like Rice Krispies)
1/2 teaspoon sea salt
Lightly grease pan with butter. In large saucepan over medium heat, melt butter. Add salt, marshmallows, unsweetened chocolate, and cocoa, and melt, stirring frequently. Stir in vanilla.
Fold in puffed rice cereal until completely coated. Fold in bittersweet chocolate. Immediately spread into pan. Gently smooth top with spatula and sprinkle evenly with salt.
Let sit until set, about 30 minutes.
Cut into squares and serve.