Begin by crushing the digestive biscuits in a food processor until they resemble fine crumbs. Mix the melted butter and cocoa powder into the crumbs until combined. Firmly press the mixture into the base of a 23cm springform tin, ensuring it's even, then refrigerate for 30 minutes to set.

In a large mixing bowl, add cream cheese, icing sugar, and cocoa powder. Mix until completely smooth, about 3-4 minutes.

Add double cream and whisk until thickened, about another 3-5 minutes, creating a luxurious texture.

Spoon the thickened cheesecake filling onto the chilled biscuit base. Smooth the top with a spatula, cover, and refrigerate for at least 4 hours.

Carefully remove the cheesecake from the tin and smooth rough edges with a butter knife.

Combine dark chocolate and 65 ml of double cream in a microwave-safe bowl. Microwave in intervals until melted and smooth.

Spread the warm dark chocolate ganache over the cheesecake, letting it flow to the edges.

In another bowl, combine white chocolate and 15 ml of double cream. Microwave until melted and silky.

Transfer white chocolate ganache into a piping bag and create a swirl pattern on the cheesecake.

Use a cocktail stick to create a spiderweb design by dragging from the center to the edges of the cheesecake.

Serve immediately or store in the fridge for up to 3 days.