Preheat the oven to 350°F and wrap the outside of a 9-inch springform pan with two layers of heavy-duty foil. Mix the chocolate graham cracker crumbs, sugar and melted butter, press firmly into the bottom of the pan and bake for 10 minutes.Let the crust cool, reduce the oven to 325°F and bring a kettle of water to a boil.
Melt the semisweet chocolate in the microwave in 30-second bursts, stirring between each, until smooth. Set it aside so it cools to warm but not hot.
Blend the cottage cheese in a food processor or blender for 2 to 3 minutes, scraping down the sides, until completely silky with no curds left.
Add the cream cheese, Greek yogurt, sugar, cocoa powder, cornstarch, espresso powder, vanilla and salt, then blend until smooth. With the machine running, pour in the melted chocolate and blend until fully combined.Add the eggs and pulse just until they disappear into the batter, about 5 pulses.
Pour the filling over the crust and tap the pan on the counter to release air bubbles. Place the springform in a roasting pan, add hot water about 1 inch up the sides and bake for 55 to 65 minutes, until the edges are set and the center still has a slight wobble.
Turn off the oven, crack the door and let the cheesecake cool inside for 1 hour. Remove it from the water bath, loosen the edge with a thin spatula, cool to room temperature and refrigerate for at least 6 hours.
For the ganache, heat the heavy cream until steaming, pour it over the dark chocolate and let it sit for 3 minutes before stirring until glossy. Cool for 10 minutes, pour over the chilled cheesecake, spread to the edges and sprinkle with mini chocolate chips.Chill for 30 minutes until the ganache sets, then release the ring and serve.