To prepare the crust

1. Preheat oven to 350 degrees.
2. Pulse graham crackers in a food processor to crumbs. Add the remaining ingredients and pulse until combined to a wet sand consistency.
3. Pat crumbs into the bottom of a 9″ springform pan and bake in the oven for 10 minutes. Allow to cool.

To prepare the cheesecake

1. Preheat the oven to 350 degrees. Start a kettle or pot of boiling water on the stove top for the water bath. You’ll need about 3 quarts of water. Wrap your springform pan with crust baked inside securely with aluminum foil. I triple layer and make sure there is no room for the water bath to leak through the pan.
2. In the bowl of a stand mixer, beat the cream cheese on medium speed until smooth, about 2 minutes. Add the sugar and cocoa powder, beating an additional 2 minutes. Add the eggs one at a time, beating on low speed until incorporated. Add the cream and vanilla, and beat until smooth and no lumps remain, about 2-3 minutes. Do not overbeat.
3. Using a rubber spatual, push your cheesecake batter through a fine mesh strainer into a bowl. Pour this mixture into your prepared springform pan.
4. Place your springform pan into a pan/dish slightly larger than the springform. I use a 10″ round cake pan, but any oven-safe dish with sides will do. Pour water into the water bath pan until the water level reaches almost halfway up the sides of the springform.
5. Bake in the oven for 1 hour and 30 minutes. The filling will barely be set but will still jiggle slightly if jostled in the oven. Allow to rest in the oven with the heat turned off and the oven door propped open slightly (I use a wooden spoon) for an additional 30 minutes. Then, transfer the springform pan to the fridge and allow to cool for at least 4 hours or overnight, if possible.
6. Once cheesecake is cool, remove from pan and prepare the ganache. Microwave the heavy cream on low heat just until it begins to lightly bubble. Remove from microwave and pour over top of the chocolate chips. Cover with Saran wrap and allow to rest for 5 minutes. Stir with a whisk until smooth and no lumps remain. Allow to cool slightly- if your ganache is too thin, it will drip down the sides of the cheesecake too quickly. Spoon the ganache over top of the cheesecake and smooth out gently with a spatula. Once you get close to the edges, push the ganache out gently, allowing little trickles of chocolate to cascade down the sides. Allow ganache to set up slightly. Extra ganache will keep in the fridge for 1 week.
7. Top with graham cracker crumbs and and a sprinkling of marshmallows. Toast with a torch or under a low-heat broiler until golden brown.