Crush the biscuits into fine crumbs using a food processor or rolling pin.

Mix melted butter and cocoa powder into the crushed biscuits until combined. Press into the base of a springform tin and chill for 30 minutes.

Blend cream cheese, icing sugar, and cocoa powder until smooth.

Incorporate double cream into the mixture, whisking until thick.

Spoon filling onto the biscuit base, smooth, and refrigerate for at least 4 hours.

Remove cheesecake from the tin and smooth edges for presentation.

Microwave dark chocolate and double cream until smooth and glossy. Cool slightly before using.

Pour dark chocolate ganache over the cheesecake and let set briefly.

Microwave white chocolate and double cream until melted and stir until creamy. Optionally add superwhite powder.

Pipe a spiraled white chocolate ganache on top of the dark ganache.

Drag a cocktail stick from the center to the edges to create a spiderweb pattern.