Prep the pan: Line the bottom of the springform pan with parchment. Lightly grease the sides.
If your air fryer basket has large openings, wrap the outside bottom with foil for stability.
Make the crust: Crush the cookies into fine crumbs. Mix with melted butter, sugar, and a pinch of salt until it resembles damp sand. Press firmly into the bottom of the pan and slightly up the sides.
Freeze for 10 minutes while you make the filling.
Preheat the air fryer: Set to 300°F (150°C) for 5 minutes. This helps the cheesecake bake evenly from the start.
Beat the cream cheese: In a mixing bowl, beat room-temperature cream cheese on medium speed until completely smooth, about 1–2 minutes. Scrape the bowl often—lumps are the enemy.
Add sugars and cocoa: Beat in granulated sugar, brown sugar, and sifted cocoa powder until smooth and fluffy.
Keep scraping the bowl to avoid streaks.
Add chocolate and dairy: Mix in the melted, slightly cooled chocolate, then add sour cream, heavy cream, vanilla, and salt. Blend on low until just combined.
Add eggs: Beat in eggs one at a time on low speed until just incorporated. Do not overmix—this limits air bubbles and cracking.
Fill the pan: Pour the batter over the chilled crust.
Tap the pan gently on the counter a few times to release air bubbles. If bubbles rise to the surface, pop them with a toothpick.
Bake in the air fryer: Place the pan in the basket. Cook at 300°F (150°C) for 28–38 minutes for a 7-inch pan (30–42 minutes for a 6-inch, slightly thicker).
The edges should be set, and the center should still jiggle like set Jell-O, not slosh.
Rest with the door cracked: Turn off the air fryer and open the drawer or door slightly. Let the cheesecake sit inside for 20–30 minutes. This gentle cooling helps prevent cracks.
Cool completely: Remove to a rack and cool to room temperature.
Run a thin knife around the edge to loosen. Chill, uncovered, for 4 hours, then cover and chill at least 4 more hours or overnight for best texture.
Add toppings (optional): For ganache, pour warm cream over chopped chocolate (1:1 by weight). Stir until smooth and slightly thickened, then spread over the chilled cheesecake.
Add berries or whipped cream if you like.
Slice and serve: Warm a sharp knife under hot water, wipe dry, and slice cleanly. Repeat between cuts for neat slices.