Graham Cracker Base-
- 1 stick (1/2 cup) unsalted butter, melted
- 1/4 cup brown sugar
- 1/4 cup white granulated sugar
- 1/4 cup honey
- 1 teaspoon pure vanilla extract
- 1-1/4 cups all-purpose flour
- 1 teaspoon baking powder
- 1/2 teaspoon salt
- 6 graham crackers, crushed (3/4 cup)
- 4 ounces (1/2 cup) semi-sweet chocolate
- 1/2 cup heavy cream
- 2 large egg whites, room temperature
- 1/2 cup white granulated sugar
- 1/8 teaspoon cream of tartar
- 1/2 teaspoon vanilla extract
- Preheat the oven to 350 degrees.
- Blondie Base: Beat the butter, sugars, and honey together until evenly incorporated. Mix in the egg and vanilla. Mix in the flour, baking powder, and salt. Stir in the graham cracker crumbs. (Do not overmix!)
- Butter a 9×9′ baking dish, and press blondie dough into the pan. Bake until lightly golden brown, 14-16 minutes.
- To make the chocolate ganache, bring heavy cream to a simmer and pour over chocolate chips in a heatproof bowl. Cover and let sit for 2 minutes. Uncover, and whisk until everything is combined, and you’re left with a chocolate ganache. Don’t worry if it’s loose, it will thicken when it chills.
- Cool the blondie base for at least 30 minutes. Once slightly cooled, pour chocolate ganache on top of the bars and spread out to the edges. Refrigerate while you prepare the frosting.
- To make the frosting, combine the egg whites, sugar and cream of tartar in a bowl set over a pan of a few inches of simmering water. Heat the mixture, whisking frequently, until it reaches 160° F with an instant-read thermometer. Transfer the mixture to the bowl of an electric mixer fitted with the whisk attachment. Whisk starting at low speed and gradually increasing to medium-high speed until stiff, glossy peaks form. Mix in the vanilla until combined.
- Top the bars with the marshmallow frosting, and use a torch to lightly toast it (you can also use the broiler, but watch it very carefully!).
- Chill overnight (or a minimum of 2 hours) to firm up the bars to be able to cut them up nicely.