- For the Graham Cracker Crust:
- 3 cups graham cracker crumbs
- ¼ cup granulated sugar
- ¼ teaspoon salt
- ¾ cup unsalted butter, melted
- For the Brownies:
- 1/3 cup Dutch-processed cocoa
- 1½ teaspoons instant espresso (optional)
- ½ cup plus 2 Tablespoons boiling water
- 2 ounces unsweetened chocolate, finely chopped
- 4 tablespoons (½ stick) unsalted butter, melted
- ½ cup plus 2 Tablespoons vegetable oil
- 2 large eggs
- 2 large egg yolks
- 2 teaspoons vanilla extract
- 2½ cups (17½ ounces) sugar
- 1¾ cups (8¾ ounces) all-purpose flour
- ¾ teaspoon salt
- 6 ounces bittersweet chocolate, cut into ½-inch pieces
- mini marshmallows
- additional graham crackers, broken into pieces
- handful semisweet chocolate chips for garnish
- Preheat oven to 350 degrees F. Line a 9x13x2 pan with foil, leaving some overhang, and then butter the foil; set aside.
DirectionsCombine the graham cracker crumbs, sugar and salt, mixing well. Add the melted butter and, using a fork, toss until the entire mixture is moist. Dump the graham cracker mixture into the prepared baking pan, pressing it into an even layer. Bake for about 15 minutes, or until golden brown.
Meanwhile, whisk cocoa, espresso powder, and boiling water together in large bowl until smooth. Add unsweetened chocolate and whisk until chocolate is melted. Whisk in melted butter and oil. (Mixture may look curdled.) 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.
Pour the brownie batter over the cooked graham cracker crust, spreading it into an even layer. Bake the brownies for 25 minutes. Then top with a single layer of mini-marshmallows. Return the brownies to the oven for another 5-8 minutes. You want the marshmallows to urn golden and melty (but not charred and desiccated) and the brownies to be cooked through (when you test them with a toothpick it should come out with a few brownie crumbs on it, but no batter).
As soon as the pan comes out of the oven, top the marshmallow layer with the pieces of graham cracker and a handful of chocolate chips, pressing down slightly so that the graham cracker and chocolate chips get nestled into the melted marshmallow.
Cool completely and then cut into squares. Store at room temperature in an airtight container.