Graham Cracker Crust

1. Adjust an oven rack to the middle position and heat the oven to 325 degrees. Pulse the graham crackers in a food processor until the crackers are broken down into coarse crumbs, about eight to ten 1-second pulses. Open and stir edges to make sure no large pieces are stuck and then repeat to make fine crumbs, another 8 to 10 times.
2. Transfer the crumbs to a medium bowl and stir in the sugar to combine; add the melted butter and toss with a fork until the crumbs are evenly moistened.
3. Use the bottom of a 1/2 cup measuring cup to press the crumbs evenly into the bottom and up the sides of a tart pan with a removable bottom, forming a crust.
4. Bake the crust until deep golden brown and fragrant, about 22 minutes. Cool the crust on a wire rack while making the filling. When cool to the touch, you can refrigerate it (covered) until you are ready to fill it.

Chocolate Ganache Filling

1. Place a wide bottom saucepan over medium-low heat and add in chopped chocolate and heavy cream. Stirring constantly melt the chocolate and cream together. Turn off the heat, and then add in the butter one tablespoon at a time. Stir in the espresso powder, salt, and vanilla extract.
2. Pour gently into the cooled graham cracker crust.
3. With a toothpick or skewer pop any bubbles that have formed in the ganache.
4. Gently place the tart pan and baking sheet into the fridge to set completely, about 2 to 4 hours.

Marshmallow Fluff

1. Place egg whites, sugar, and cream of tartar in a heatproof bowl – or I use the metal bowl from my standmixer. Set bowl over a saucepan filled with two inches of simmering water creating a mock-double boiler. Do not let it touch the water.
2. Whisk constantly until sugar is dissolved and mixture has thinned out, about 6 minutes. The mixture will be thick at first, then thin out and appear frothy on top because of the air that you have added to the egg whites.
3. Using an instant read thermometer the temperature should read 160°F (71°C) to ensure that the egg whites are cooked through. It may take longer than 6 minutes, depending on how fast the water in your double boiler is boiling underneath. Adjust the heat on the water as necessary.
4. Remove from heat. (No need to let it cool down before continuing.) Add the vanilla extract and salt, then using a handheld or stand mixer fitted with a whisk attachment, beat on high speed until stiff glossy peaks form, about 5 to 8 minutes. The sides of the bowl will be cool and the marshmallow fluff will be cool and glossy.
5. Meringue can be spread, piped, or swirled onto cakes, cupcakes, and other confections. Serve immediately OR torch it with a kitchen torch for a delicious toasted marshmallow topping. (Do not place in the oven under the broiler—it will melt the marshmallows and the chocolate ganache.)

Slice and serve the chocolate s’mores tart!!