Gluten Free S'mores Brownies
Ingredients
Brownie Layer
1/2 cup plus 2 tablespoons (88 g) all-purpose gluten-free flour
1/8 teaspoon xanthan gum (omit if your blend already contains it)
1/2 teaspoon baking powder
1/4 teaspoon baking soda
1/2 teaspoon kosher salt
1/3 cup (27 g) Dutch-processed unsweetened cocoa powder
1 cup (200 g) sugar
8 tablespoons (112 g) unsalted butter, melted and cooled
1 egg (60 grams out of shell) plus 1 egg yolk (30 grams) at room temperature, beaten
1/2 teaspoon pure vanilla extract
Marshmallow Layer
1 packet (1 scant tablespoon) unflavored powdered gelatin
1/2 cup (4 fl. oz.) cool water
1 cup (200 g) sugar
1/8 teaspoon cream of tartar
1/2 teaspoon pure vanilla extract
1/8 teaspoon kosher salt
Chocolate Layer
4 ounces bittersweet chocolate, chopped
3 ounces gluten free graham crackers, crumbled
Instructions
Preheat your oven to 350°F. Grease the bottom of a 9-inch square baking pan and line it with unbleached parchment paper that overhangs two opposite sides of the pan. Grease the paper, then place another, crisscrossed sheet of parchment paper on top that overhangs the other two sides. Set the pan aside.
Make the brownie layer. In a large bowl, place the flour blend, xanthan gum, baking powder, baking soda, salt, cocoa powder and sugar, and whisk to combine well. Add the butter, egg and egg yolk, and vanilla, and mix well. Spread the batter evenly in the prepared pan and tap on the counter to break any trapped air bubbles. Place the pan in the center of the oven and bake for 22 to 25 minutes, or until a toothpick inserted in the center comes out with, at most, a few moist crumbs attached. Allow to cool completely in the pan (if you’re impatient like I am, after a few minutes stick it in the freezer).
Make the marshmallow layer. In a small bowl, place the gelatin and 1/4 cup (2 fluid ounces) water and mix to combine well. Set the bowl aside and allow the gelatin to swell as it stands. Once the gelatin has swelled, transfer it to the bowl of a stand mixer (or a large bowl to use with a hand mixer).
In a medium, heavy-bottom saucepan, place the remaining 1/4 cup (2 fluid ounces) water, sugar and cream of tartar, and whisk to combine well. Cook the sugar mixture over medium-high heat until it reaches the softball stage, between 238°F and 240°F, on an instant read thermometer. Remove the saucepan from the heat immediately, and pour the cooked sugar mixture down the side of the bowl of the stand mixer into the gelatin mixture. Whisk to combine and allow the mixture to cool briefly. It will bubble. Add the vanilla and salt, and beat the mixture on medium-high speed with the whisk attachment (or with a hand mixer) until the mixture is white, thick and glossy. It should nearly triple in size. It is ready when the mixture pours off the whisk (or beaters) very slowly when the attachment is raised. Scrape the marshmallow mixture onto the chilled brownies, and spread into an even layer. Place in the refrigerator until set (about 3 hours).
Once the marshmallow layer is set, remove the brownies from the pan by lifting up on the overhung pieces of parchment paper. Melt the chocolate in a small heat-safe bowl over a double boiler (or in the microwave on 70% power in 30 second intervals) until smooth. Pour the melted chocolate in an even layer over the top of the marshmallows, and immediately sprinkle the graham cracker crumbs over the top. Allow to sit until the chocolate sets. Slice into 16 squares with a large, serrated knife before serving. The chocolate layer will crack somewhat unevenly.
Brownie layer adapted from the Make-Your-Own Brownie Mix on page 199 of Gluten-Free on a Shoestring Quick & Easy: 100 Recipes for the Food You Love–Fast! (Da Capo 2012).