1. Preheat the oven to 325°F and lightly grease a 9-inch springform pan. Wrap the outside of the pan with a double layer of foil.

2. Mix the crushed chocolate cookies with the melted butter until evenly combined. Press into the bottom of the springform pan and bake for 8 to 10 minutes. Cool completely.

3. In a large bowl, beat the cream cheese until smooth. Add the granulated sugar and mix on low speed until creamy.

4. Add the sour cream, vanilla extract, peppermint extract, 1 tablespoon espresso powder, and 4 ounces melted semisweet chocolate. Mix just until smooth.

5. Add the eggs one at a time, mixing on low speed after each addition until just combined.

6. Pour the filling over the cooled crust and smooth the top. Place the springform pan inside a larger roasting pan and add hot water halfway up the sides.

7. Bake for 60 to 70 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 rest inside for 1 hour.

8. Remove the cheesecake from the water bath and cool completely on a wire rack. Refrigerate for at least 6 hours or overnight.

9. Heat 1/2 cup heavy cream until hot. Pour over 4 ounces semisweet chocolate with 1 teaspoon espresso powder and the cocoa powder, if using. Stir until smooth and let cool slightly. Spread over the chilled cheesecake.

10. Beat the heavy whipping cream with powdered sugar until soft peaks form. Pipe or spoon around the edges of the cheesecake, then top with crushed peppermint candies and fresh mint leaves if desired.

11. Chill for 15 to 20 minutes before slicing and serving.