Step 1: Prep and Preheat
Preheat your oven to 325°F (160°C).
Wrap the outside of a 9-inch springform pan with two layers of foil to prevent leaks.
Lightly grease the inside.

Step 2: Make the Crust
In a bowl, mix the chocolate cookie crumbs with melted butter until well combined.
Press into the bottom of the springform pan and slightly up the sides.
Bake for 8–10 minutes, then set aside to cool.

Step 3: Prepare the Filling
In a large bowl, beat cream cheese and sugar until smooth and fluffy.
Add sour cream, heavy cream, orange zest, and orange juice. Mix until just combined.
Add eggs one at a time, beating gently after each.
Stir in vanilla and melted chocolate until well blended.

Step 4: Bake the Cheesecake
Pour filling over the prepared crust.
Place the pan into a larger roasting pan and fill the outer pan with hot water halfway up the sides of the springform.
Bake for 60–70 minutes, or until edges are set and the center is slightly jiggly.
Turn off the oven, crack the door, and let the cheesecake cool inside for 1 hour.

Step 5: Chill Completely
Remove from the oven and water bath. Let cool to room temperature.
Cover and refrigerate for at least 6 hours or overnight for best texture.

Step 6: Make the Ganache Topping
In a small saucepan, heat heavy cream until steaming (not boiling).
Remove from heat and add chopped chocolate. Let sit for 2 minutes, then stir until smooth.
Stir in orange zest.
Cool slightly and pour over the chilled cheesecake. Spread evenly and let set for 15 minutes in the fridge.

Step 7: Garnish & Serve
Garnish with chocolate curls, orange slices, or extra zest if desired.
Slice with a warm knife for clean cuts and serve chilled.