Ingredients
1/3 cup Dutch-processed cocoa
1 1/2 teaspoons instant espresso (optional)
1/2 cup plus 2 tablespoons boiling water
2 ounces unsweetened chocolate, finely chopped
4 tablespoons (1/2 stick) unsalted butter, melted
1/2 cup plus 2 tablespoons vegetable oil
2 large eggs
2 large egg yolks
2 teaspoons vanilla extract
2 1/2 cups sugar
1 3/4 cups unbleached all-purpose flour
3/4 teaspoon table salt
6 ounces bittersweet chocolate, cut into 1/2-inch pieces
1 cup (about 10) graham crackers, broken to 1/4 inch pieces (but not crumbs!)
1 cup mini marshmallows
Directions
Heat oven to 350F degrees. Make a foil sling for your 13 x 9 inch pan. Spray with nonstick cooking spray.
Whisk cocoa, espresso powder (if using), and boiling water together in large bowl until smooth. Add unsweetened chocolate and whisk until chocolate is melted. Whisk in melted butter and oil. Add eggs, yolks, and vanilla and continue to whisk until smooth and homogeneous. Whisk in sugar until fully incorporated. Add flour and salt and mix with rubber spatula until combined. Fold in bittersweet chocolate pieces.
Scrape batter into prepared pan and sprinkle with graham cracker pieces and mini-marshmallows. Push marshmallows a little into the batter, instead of having them just rest on top. B bake until toothpick inserted halfway between edge and center comes out with just a few moist crumbs attached, 35-40 minutes. If you notice the marshmallows getting dark or starting to scorch, cover with aluminum foil.
Transfer pan to wire rack and cool at least 2 hours. Using foil overhang, lift brownies from pan. Return brownies to wire rack and let cool completely, about 1 hour more. Cut into 2-inch squares and serve.
