Combine the crushed chocolate cookies and melted butter in a bowl. Stir until all crumbs are evenly coated and stick together.
Press the crust mixture firmly into the bottom of a springform pan. Pop it in the fridge for about 15 minutes so it sets nice.
In a large bowl, beat the softened cream cheese with a mixer until smooth and creamy.
Mix in powdered sugar, orange zest, orange juice, and vanilla extract until the whole thing is blended well.
In a different bowl, whip the heavy cream until stiff peaks form then gently fold that into your cream cheese mixture.
Fold the melted dark chocolate into the filling just until it’s marbled.
Pour the filling over your crust and smooth the top.
Put it back in the fridge for at least 4 hours until fully set.
Notes
Refrigerate leftovers tightly covered for up to 3 days, or wrap slice-by-slice before freezing for up to a month. Thaw overnight in the fridge before serving.