Make the crust

1. Preheat oven to 350°F (175°C).

2. Pulse whole Oreos (filling included) in a food processor until they form fine crumbs. Measure 2 cups.

3. Stir the cookie crumbs with the melted butter until evenly moistened. Press the mixture firmly into the bottom (and optionally a little up the sides) of an 8- or 9-inch springform pan. Use the flat bottom of a measuring cup to compact the crust.

4. Bake the crust for 10 minutes, then remove and let cool to room temperature. Chill in the fridge briefly if you want to speed things up. Lower the oven temperature to 325°F (163°C) for the cheesecake.

Prepare the cheesecake batter
5. Place the springform pan inside an oven-safe roasting/turkey bag or wrap it well in foil and fold down the top of the bag so it won’t cover the batter later — this helps keep water out of the pan. Set aside.
6. In a large bowl, beat the room-temperature cream cheese on medium speed until very smooth, about 2–3 minutes. Scrape the bowl as needed to remove lumps.
7. Add the sugar, vanilla, and espresso; mix until combined and smooth. Taste to check the coffee intensity and adjust with a touch more espresso if desired (avoid adding extra liquid).
8. Add the eggs one at a time, mixing gently after each addition until just incorporated. Mix for only about 1 minute after the last egg — overbeating introduces air and can cause cracking.

Assemble and bake in a water bath
9. Pour the filling over the cooled crust and level the top. Tap the pan gently on the counter to release large air bubbles.
10. Set the wrapped springform pan into a larger roasting pan. Carefully pour hot water into the outer pan to reach about 1 inch up the outside of the springform (avoid splashing water into the cheesecake).
11. Bake at 325°F (163°C) for the times below, until the edges are set and the center has a slight wobble when you jiggle the pan:

• 8-inch springform: about 75–85 minutes

• 9-inch springform: about 65–75 minutes

12. When done, turn the oven off. Remove the roasting pan from the oven and carefully lift the springform (still in its bag or foil) out of the water. Place the cheesecake on a baking sheet and return it to the oven with the door cracked for about 60–90 minutes to cool slowly.

Chill and unmold
13. After the slow oven cooling, transfer the cheesecake to the refrigerator and chill, loosely covered, overnight.
14. To remove, run a thin knife around the edge, release the springform, and slide the cheesecake onto a cake board or serving plate. Use a small spatula to loosen any spots that cling to the pan.

Make the ganache
15. Place chopped chocolate or chocolate chips in a heatproof bowl. In a small saucepan, bring the heavy cream to a gentle boil. Pour the hot cream over the chocolate and let sit for 60 seconds, then stir until smooth and glossy. Let the ganache cool 5–7 minutes so it thickens slightly before pouring.

Finish and serve
16. Spoon or pour the ganache over the chilled cheesecake and use an offset spatula to spread it evenly. Decorate with chocolate shavings if desired.
17. Store leftovers covered in the fridge for up to 4–5 days.