You will absolutely love these S'mores Brownies that have all the goodness of traditional s'mores and more! There's a thick layer of fudgy brownie over a crisp graham cracker crust with a toasted marshmallow topping. This is the perfect treat to bring to any Summer party!
Make the crust. Combine graham cracker crumbs and brown sugar in a medium bowl. Add cooled melted butter and stir until evenly combined. If you are making your own crumbs, place 150g graham crackers in the food processor and pulse until it resembles coarse bread crumbs. Press the crumb mixture evenly into the bottom of the pan. Bake for about 10 minutes until lightly golden and feels dry. Transfer to a wire rack to cool..
Make the brownie batter. Combine eggs, sugar, vanilla and salt in a large bowl and whisk vigorously until pale, thick and creamy-looking. This will take 1-2 minutes using a wire whisk. It doesn’t need to be very voluminous, but it should be mixed well enough that most of the sugar begins to dissolve.
Combine chopped chocolate and butter in a heatproof bowl set over a saucepan with ½-inch of simmering water and stir occasionally until melted and smooth, or melt in the microwave at 50% power in short bursts with frequent stirring. Add this warm chocolate mixture to the egg mixture and whisk or stir until evenly combined, smooth and glossy.
Sift over the flour and stir it in until just combined. Pour this batter over the baked graham cracker crust and spread it out evenly. Bake 20-25 minutes until puffed and shiny. A skewer inserted into the middle should come out with a few moist, sticky crumbs attached (not wet batter). It will sink a bit on cooling.
Scatter marshmallows evenly over top, then sprinkle over chocolate chunks and place the pan under the broiler for just 30 seconds until the marshmallows look golden brown and toasty. Do not look away and watch carefully as they can burn easily. Remove from oven and transfer to a wire rack. Sprinkle crushed graham crackers over top and let cool for at least 30 minutes before slicing with an oiled knife.