Instructions

1. To make the crust:
2. Preheat oven to 350 F. Spray a 9-inch springform pan with nonstick cooking spray.
3. In a medium bowl, stir together the graham cracker crumbs and sugar.
4. Pour the melted butter over the mixture and stir until the crumbs are evenly moistened.
5. Press into an even layer in the bottom of the prepared springform pan.
6. Bake for 12 minutes, or until set.
7. Transfer the pan to a wire rack and cool to room temperature.
8. Reduce oven temperature to 325 F.
9. To make the filling:
10. Add the chocolate to a microwave-safe bowl and heat in 30 second intervals at 50% power, stirring in between each interval, until the chocolate is melted and smooth. Cool until just barely lukewarm, stirring occasionally.
11. Combine the cream cheese, sugar, and salt in the bowl of your food processor and pulse until smooth.
12. With the machine running, pour the heavy cream through feed tube and process just until blended.
13. Again, with the machine running, add the melted chocolate and then the eggs, one at a time, blending and scraping down the sides of the bowl after each addition until the mixture is smooth.
14. Pour the batter over the cooled crust.
15. Bake for about 55 minutes, or until the outer edge is slightly puffed and the center is barely set (the center will jiggle slightly when the pan is gently shaken). Transfer the pan to a wire rack. Run a small sharp knife around the cake to loosen it from the pan.
16. Let cool slightly then refrigerate for at least 8 hours. (I left mine uncovered in the fridge until it was cold, then used plastic wrap to cover the pan.)
17. To make the topping:
18. In a large metal bowl (I used the bowl for my stand mixer), combine the sugar, egg whites, water, cream of tartar and salt.
19. Set the bowl over a pan of simmering water and whisk constantly until the sugar dissolves and the mixture feels hot to the touch, about 3 minutes. Remove the bowl from the pan and add the marshmallows; let stand for a few minutes until the marshmallows soften.
20. Place the bowl back over the pan of simmering water and beat the topping with a hand mixer for 4-5 minutes, or until stiff, shiny peaks form. Beat in the vanilla.
21. Let the topping cool just slightly (don't wait too long or it'll set and you won't be able to spread it).
22. Meanwhile, remove the sides of the pan from the cheesecake.
23. Transfer the topping onto the cheesecake; use a spatula to spread it to the edges.
24. Let stand for about 15 minutes, or until set. Use a kitchen torch to toast the topping lightly. (You could also do this under your broiler but keep a VERY close eye on it, it'll go from brown to burnt quickly.)
25. Transfer the cheesecake to the fridge and chill well before serving.