For Crust

1. Preheat oven to 350 degrees.
2. Cover the bottom and sides of a 9 inch springform pan with aluminum foil, wrapping the pan up to the edges so that no water can leak in from the waterbath. Use a double layer of foil if you like.
3. Pulse the Oreo pieces in a food processor until finely ground. If you don’t have a food processor, you can place the cookies in a ziplock bag and use a rolling pin to crush the cookies into fine bits. Add sugar and the pinch of salt, pulse to combine.
4. Pour crumbs in a medium bowl and add melted butter. Stir together with a fork until evenly coated.
5. Scoop the mixture into the springform pan and use your hands to press the crust evenly across the bottom and halfway up the sides of the pan. Use the backside of a measuring cup to press the crust down firmly.
6. Bake for 8-10 minutes on the lower third of the oven.
7. Remove from the oven to cool slightly and reduce the oven temperature to 325 degrees.

For Cheesecake Filling

1. In the bowl of a food processor fitted with the paddle attachment, beat together the cream cheese, sugar, sour cream and heavy cream for about 5 minutes on low speed. Mixture should be smooth and creamy.
2. With mixer on low speed, add melted chocolate and unsweetened cocoa powder, followed by the salt.
3. Mix on medium speed for 30 seconds to combine well.
4. Reduce mixer to low speed and add eggs, one at a time. Scrap down sides of bowl after each addition.
5. Once eggs are fully incorporated, add the vanilla and cooled espresso. Beat on low speed until just combined.
6. Place the springform pan with cookie crust into a larger pan or roasting pan. Pour the cheesecake filling over the crust, smoothing out the top with an off set spatula.
7. Heat water in a saucepan until boiling and pour into the surround pan, being careful not to spill any on the cheesecake. Fill the surrounding pan so that the water goes up halfway around the springform pan.
8. Place in the oven and bake at 325 degrees for an hour and fifteen minutes. After one hour, check the cheesecake often for cracks. If cracks begin to form, turn off the oven and begin the cooling process.
9. If you want a firmer cheesecake, bake it for closer to an hour and thirty minutes, checking often.
10. Once the cheesecake is baked, turn off the oven and leave the cheesecake in the warm oven for one hour.
11. Remove from the oven and take the springform pan out of the waterbath. Chill in the refrigerator for 6 hours or overnight for best results.

For Gananche

1. Place chopped chocolate in a medium bowl.
2. Heat heavy cream over medium high heat until simmering.
3. Pour half of the hot cream over the chocolate and allow to sit for 1 minute.
4. Whisk quickly and then add remaining cream.
5. Stir together with a whisk until smooth and glossy.
6. Add butter and stir until butter is fully incorporated.
7. Cool to room temperature before spreading the ganache over the top of the cooled cheesecake.
8. Add chocolate shavings if desired.
9. Allow the ganache to set before slicing.
10. For a clean cut, use a sharp knife and press firmly down and then out from the edge of the cheesecake. Do not pull up with the knife. Run the knife under warm water and wipe with a towel in between each slice.