Preheat oven to 350°F (175°C). Combine chocolate graham cracker crumbs with melted butter and press firmly into the bottom of a 9-inch springform pan.
Beat cream cheese and sugar until smooth and creamy. Mix in cocoa powder until fully incorporated.
Add eggs one at a time, mixing gently after each. Stir in sour cream and melted dark chocolate until smooth.
Gently swirl raspberry jam into the batter. Pour over the prepared crust and bake for 55–65 minutes until edges are set and center slightly jiggles.
Turn off oven and cool cheesecake inside with door slightly open for 1 hour. Cool completely, then refrigerate at least 4 hours or overnight.
