Preheat the oven to 325°F.
Process graham crackers into crumbs with a food processor. Combine with melted butter.
Grease an 8×8 square baking pan or dish and press the graham cracker mixture into an even layer on the bottom of the pan.
In a bowl (or stand mixer) beat the cream cheese until whipped and creamy.
Add granulated and brown sugar and mix well.
Melt chocolate chips over a double boiler and add to cream cheese mixture.
Add egg yolks to the mixture.
Add the cocoa powder, cornstarch and salt and mix well.
Add the Dragon’s Milk Reserve and vanilla extract and mix well.
Pour the mixture overtop the graham cracker layer in the baking pan.
Bake for 45 minutes @ 325°F. (The edges should be set, but the center will still be a bit loose when you remove it from the oven. It will set the rest of the way as it cools.)
Allow to cool completely to room temperature.
In a separate bowl, break the chocolate baking bar into pieces and add the heavy cream and bourbon. Microwave at 50% power in 30 second intervals, stirring in between until completely melted and well combined.
Pour the ganache mixture in an even layer over the cooled cheesecake and allow to rest in the fridge overnight (or at least 4-5 hours).
When ready to serve, cut into individual bars.
Top each bar with a tablespoon of marshmallow topping and use a kitchen torch to nicely brown the marshmallow.