Mix the crushed chocolate graham crackers and melted butter in a bowl. Press the mixture into the bottom of a springform pan to form the crust.
In a large mixing bowl, beat the softened cream cheese and granulated sugar until smooth. Add the cocoa powder, eggs, sour cream, and melted dark chocolate. Mix until fully combined.
Pour the filling over the crust in the springform pan. Spread the raspberry jam on top.
Bake in the preheated oven for 60 minutes or until set. Let cool before serving.
Notes
Chill the cheesecake in the refrigerator for at least 4 hours before serving for the best texture.