Preheat your oven to 350°F (175°C).

In a medium bowl, mix your graham cracker crumbs with melted unsalted butter until the mixture resembles wet sand. Press into the springform pan and bake for 10 minutes. Allow to cool.

Beat the cream cheese until smooth, then gradually add sugar, fresh orange zest, and juice, mixing until creamy.

Melt the dark chocolate in a microwave-safe bowl in 30-second intervals. Allow to cool slightly, then fold it into the cream cheese mixture.

Whip the heavy cream to soft peaks, then fold into the chocolate cream cheese mixture gently.

Pour the filling into the cooled crust, smooth the top, cover with plastic wrap, and refrigerate for at least 4 hours or overnight.

Melt additional dark chocolate and drizzle over the cheesecake, garnish with orange slices, and serve chilled.