In a medium bowl, combine chocolate graham cracker crumbs, melted butter, sugar, and salt until evenly moistened.

Press the mixture firmly into the bottom and slightly up the sides of a 9-inch springform pan.

Bake the crust at 325°F for 8–10 minutes for extra structure. Set aside to cool.

Preheat oven to 325°F. Wrap the outside of the springform pan tightly with heavy-duty foil to prepare for a water bath.

In the bowl of a stand mixer fitted with the paddle attachment, beat the cream cheese until completely smooth.

Add sugar and espresso powder and mix just until combined, scraping down the sides of the bowl as needed.

Slowly pour in the slightly cooled, melted chocolate while mixing on low speed until fully incorporated.

Add sour cream and vanilla bean paste. Mix on low until combined, then add the heavy cream and mix briefly.

Add eggs one at a time, mixing on low speed after each addition and scraping the bowl as needed. Do not overmix.

Pour the cheesecake filling into the prepared crust and smooth the top.

Place the springform pan inside a large roasting pan. Carefully pour hot water into the roasting pan until it reaches halfway up the sides of the springform pan.

Bake for 60–70 minutes, until the edges are set and lightly golden and the center still jiggles slightly when gently shaken.

Turn off the oven, crack the door open, and allow the cheesecake to cool in the oven for 2 hours.

Remove the cheesecake from the water bath and foil. Cool completely at room temperature.

Refrigerate for at least 4 hours, preferably overnight, before slicing.