Preheat the oven to 350°F (175°C). Wrap the outside of a 9-inch springform pan with aluminum foil and spray the inside with cooking spray.

In a medium bowl, combine chocolate graham cracker crumbs and melted butter. Press this mixture into the bottom of the prepared springform pan to form the crust.

Bake the crust for 8-10 minutes, then let it cool completely. Lower the oven temperature to 325°F (160°C).

In a large mixing bowl, beat the cream cheese with sugar until smooth. Blend in the eggs, one at a time, mixing well after each addition, then add the vanilla extract and sour cream. Mix until everything is combined and smooth.

Pour the cream cheese filling over the cooled crust.

Bake in a water bath for 1 hour, or until the edges are set and the center jiggles slightly. Turn off the oven and let it sit for 1 hour in the oven to cool gradually. Then remove from the oven and chill in the refrigerator for at least 4 hours, preferably overnight.

To make the ganache, heat the heavy whipping cream until just boiling. Pour the hot cream over the chopped chocolate and let it sit for 2 minutes. Stir until smooth and glossy.

Pour the ganache over the chilled cheesecake and let it set before cutting into slices. Serve chilled and enjoy!