• Preheat the oven to 180°C (350°F). Line the bottom of a 9-inch springform pan with parchment paper and lightly grease the sides.

Bake the Oreo crust

• Pulse the Oreos in a food processor until fine crumbs form. Alternatively, crush them in a Ziplock bag using a rolling pin or cup.
• In a small bowl, mix the Oreo crumbs, espresso powder, and melted butter until well combined.
• Press the crumb mixture firmly into the bottom of the prepared pan. Bake at 180°C (350°F) for 8 minutes, then set aside to cool. Turn the oven down to 140°C (280°F).

Mix the filling

• In a large bowl, use a hand mixer on low speed to beat the room-temperature cream cheese, sugar, sour cream, and vanilla extract until smooth.
• Whisk the eggs in a small bowl, then pour into the cream cheese batter. Mix on low speed just until combined. Avoid overmixing so excess air is not whipped into the batter.
• Sift in the cornstarch and add the espresso powder. Mix gently until smooth, scraping down the sides of the bowl with a spatula so no lumps remain.

Bake and chill

• Pour the filling over the cooled crust. Tap the pan on the counter a couple of times to bring any trapped air bubbles to the surface.
• Bake at 140°C (280°F) for 60 to 70 minutes. The edges should look set, but the center will still have a slight wobble.
• Turn off the oven, prop the door open halfway, and let the cheesecake cool inside for 1 to 2 hours. Cover the pan with plastic wrap and chill in the fridge for at least 5 hours, or overnight.

Add the toppings

• For the ganache, heat the dark chocolate, heavy cream, and espresso powder in the microwave in 30-second bursts. Let it sit for 10 minutes, then whisk until smooth.
• Pour over the chilled cheesecake, smooth it out, and return to the fridge for 15 minutes to set.
• Whip cold heavy cream, powdered sugar, espresso powder, and vanilla extract until stiff peaks form. Pipe the whipped cream around the edges with a star tip and finish with chocolate shavings.