In a food processor, pulse the Oreo cookies until finely ground, resembling sand. Add the melted unsalted butter and pulse again until well combined.

Transfer the crumb mixture into a mini cheesecake pan, evenly spreading it across the bottom. Pack the crumbs tightly to form a firm crust.

In a saucepan, heat the heavy cream over medium heat until steaming but not boiling—about 3-5 minutes. Pour hot cream over chopped chocolate and let sit for 1 minute before whisking until smooth.

Carefully pour the ganache over the prepared Oreo crust and spread evenly with a spatula.

Cover and refrigerate for about 1-3 hours for mini dessert pans, or 6-8 hours for larger versions.

Once chilled, remove from the pan, slice with a sharp knife, and serve topped with whipped cream or fresh berries.