Preheat the oven to 350°F (175°C).
Prepare the crust by mixing the chocolate cookie crumbs and melted butter. Press mixture into the bottom of a springform pan.
Bake the crust for 10 minutes, then let it cool.
In a mixing bowl, beat the softened cream cheese until smooth. Add sugar and vanilla extract, mixing until combined.
Add in the eggs, one at a time, mixing thoroughly after each addition.
Pour in the melted dark chocolate and cornstarch, mixing until fully combined.
Gently fold in the raspberries, making sure they are evenly distributed throughout the batter.
Pour the batter over the cooled crust and smooth the top.
Bake the cheesecake for 50-60 minutes, or until the center is slightly jiggly.
Turn off the oven and let the cheesecake cool inside for 1 hour with the door ajar.
Chill the cheesecake in the refrigerator for at least 4 hours, or overnight for best results.