Preheat your oven to 350°F (175°C) and line a 12-cup muffin pan with cupcake liners.

Combine Oreo crumbs and melted salted butter in a mixing bowl. Press into muffin liners and bake for 5 minutes.

Melt bittersweet chocolate in a microwave-safe bowl in 30-second intervals, stirring until smooth.

Beat cream cheese, sugar, and cocoa powder in a large bowl until creamy. Gradually add sour cream, whipping cream, and vanilla, mixing until smooth.

Stir melted chocolate into the mixture, then add eggs one at a time, mixing gently to avoid cracks.

Fill muffin liners with cheesecake filling below the top and tap to remove air bubbles.

Bake for 18-20 minutes until puffed and the tops appear dry.

Cool in the pan for 10 minutes, then transfer to a wire rack to cool completely before refrigerating.

Heat heavy cream in a saucepan until just boiling, then pour over dark chocolate chips and stir until smooth.

Whip the remaining heavy cream with powdered sugar and cocoa until stiff peaks form.

After chilling, top mini cheesecakes with ganache and a dollop of whipped cream.