Preheat the oven to 350 F

In a food processor or with a ziploc bag/rolling pin, grind ~2 packages of graham crackers until fine

As soon as the crackers are fine, measure out two cups. Combine 2 cups of graham cracker crumbs with melted butter, salt, and sugar. Mix until the ingredients are all incorporated.

In the base of the cake pans, evenly distribute the graham cracker crust. After distributing, press the mixture down with a measuring cup or other flat surface until it forms a very compact layer

Place the pans in the oven and bake for 10 minutes (or until slightly golden) and set aside to cool while you make the cake

Combine the sugar, flour, cocoa powder, baking soda, baking powder, and salt into a bowl. Stir together with a whisk until evenly combined

Add the vanilla, eggs, buttermilk, and oil and stir until combined

Once combined, add the hot coffee. Stir quickly to ensure the hot coffee is evenly distributed. The batter will be very thin

Pour the batter into 3 greased and floured 6" pan or 2” cake pans. Cook for ~25 minutes on 350 F – make sure a toothpick comes out clean

Set aside to cool

To make the ganache, add chocolate, butter, salt, and vanilla into a bowl. Set asideIn a small pan over medium heat, heat cream and sugar until hot but just before boiling

Pour the heated cream and sugar over the bowl of chocolate and let it set for 1 minute. Stir until smooth

Set in the fridge until cooled but not hard

Use a double boiler or create one using a bowl and pan. Fill the pan with ~1” warm water and place a bowl over the pan so it can heat the egg whites with the steam, but it should not touch the bottom

Add egg whites, sugar, and cream of tartar to the bowl. Place the bowl over the warm water. The pan should not touch the bottom but be heated by the steam

On low, heat the egg white mixture stirring constantly until gently warmed and the sugar is dissolved. Be very careful at this stage to not let the egg whites cook. Scrape the sides of the pan, stir constantly, and remove when sugar dissolves

Once dissolved, whip the egg whites on high until stiff peaks form. The mixture will be very glossy and thick. When you place the whisk into the eggs and pull up, it should create a peak.

Place a layer of the cake graham cracker crust down. Pipe a layer of ganache around the rim of the cake layer then fill the middle with marshmallow cream. The ganache should act as something to hold in the marshmallow cream. Repeat on top of the second layer

Coat the cake with chocolate ganache. (At this phase we also added the remaining marshmallow cream and toasted for additional decoration but this is totally optional)

Optional: Top with marshmallows and toast