1. Preheat your oven to 325°F (165°C). Prepare a 9-inch springform pan by greasing it lightly.
2. In a medium bowl, combine the chocolate cookie crumbs and melted butter. Press the mixture into the bottom of the prepared pan to create the crust. Set aside.
3. In a large mixing bowl, beat the cream cheese until smooth. Add the sugar and flour, mixing until well combined.
4. Blend in the eggs one at a time, ensuring each is fully incorporated before adding the next. Stir in the sour cream and vanilla extract.
5. Gently fold in the melted semisweet chocolate, mixing until the batter is smooth and even in color.
6. Pour the cheesecake batter over the crust, smoothing the top with a spatula. Bake for 55-60 minutes, or until the center is set but still slightly jiggly.
7. Turn off the oven and let the cheesecake cool inside for 1 hour, preventing any cracks from forming.
8. In a small saucepan, heat the heavy cream over medium heat until it just begins to simmer. Remove from heat and add the chopped dark chocolate. Stir until smooth.
9. Pour the chocolate ganache over the cooled cheesecake, spreading it evenly over the top. Refrigerate for at least 4 hours before serving, allowing the flavors to meld beautifully.

One of Mama Lou’s secrets was to always let the cheesecake rest overnight, allowing the flavors to deepen and the texture to become even more luxurious.