Preheat your oven to 325°F (160°C) and prepare a 9-inch springform pan by lightly greasing it.

In a mixing bowl, combine chocolate graham cracker crumbs and granulated sugar. Stir in the melted butter until well-coated. Press this mixture evenly into the bottom of the prepared pan to form the crust. Bake for about 10 minutes, then remove it from the oven to cool.

In a large bowl, beat the softened cream cheese with an electric mixer until smooth and creamy. Gradually add the granulated sugar and cocoa powder, mixing until well incorporated.

Add the eggs one at a time, mixing on low speed until just blended. Then add the vanilla extract and melted dark chocolate, mixing until smooth.

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

Pour the filling over the cooled crust and smooth the top with a spatula. Bake for 55-60 minutes or until the edges are set but the center is slightly jiggly.

Turn off the oven, crack the door open, and let the cheesecake cool in the oven for an hour. Then refrigerate for at least 4 hours, preferably overnight.

Before serving, you can garnish with additional raspberries and a dusting of cocoa powder or whipped cream, if desired. Slice, serve, and enjoy!