1. Preheat the oven to 325°F and lightly grease a 9-inch springform pan.

2. Mix the crushed chocolate cookies with melted butter until evenly combined.

3. Press the crust mixture firmly into the bottom of the pan and bake for 10 minutes, then let it cool.

4. Beat the cream cheese until smooth, then mix in the sugar until creamy.

5. Add the sour cream, Kahlua, and vanilla extract, mixing until fully combined.

6. Add the eggs one at a time, mixing on low speed just until incorporated.

7. Pour the filling over the cooled crust and smooth the top.

8. Bake for 50 to 60 minutes, until the edges are set and the center still slightly jiggles.

9. Turn off the oven, crack the door open, and let the cheesecake rest inside for 1 hour.

10. Cool completely at room temperature, then refrigerate for at least 6 hours or overnight.

11. Heat the heavy cream until hot, pour it over the chopped semi-sweet chocolate, and stir until smooth.

12. Spread the chocolate topping over the chilled cheesecake and refrigerate for 20 minutes before slicing.