Preheat the oven to 350°F (175°C).

Prepare the crust by mixing chocolate cookie crumbs with melted butter in a bowl until combined.

Press the mixture firmly into the bottom of a 9-inch springform pan and bake for 10 minutes; then set aside to cool.

In a large mixing bowl, combine softened cream cheese and sugar until smooth and creamy.

Add sour cream, vanilla extract, melted dark chocolate, and cornstarch; mix until well-blended.

Gently fold in the fresh raspberries, being careful not to break them apart.

Pour the filling over the cooled crust and spread it evenly.

Bake in the oven for 50-60 minutes or until the center is set but slightly jiggly.

Once done, turn off the oven and crack the door open, allowing the cheesecake to cool inside for an hour.

Remove from the oven and refrigerate for at least four hours, preferably overnight, before serving.