Grease the sides and bottom of a 23cm (9-inch) springform tin and set aside.

For the biscuit base: tip the oreo biscuits into a food processor and blitz into fine crumbs. Add the melted butter and whizz again until you have the desired crumbly consistency. It should resemble damp sand.

Tip into the prepared tin and use a glass (or the back of a spoon) to pat into a smooth and compact layer on the base and ⅔ the way up the sides (don’t worry, it doesn’t have to be perfect). Cover and chill in the fridge whilst you make the filling.

For the cheesecake filling: put the cream cheese into a large bowl and sift in the icing sugar and cocoa powder. Whisk using an electric whisk until smooth. You can also do this using a stand mixer. 

Pour in the slightly cooled melted chocolate and whisk to combine.

In a separate bowl, whisk the double cream and vanilla extract until you have soft peaks - take care not to overwhisk as you will mix it further when you add to the other ingredients.

Add the cream to the chocolate cheesecake mixture and gently fold to combine. 

Spoon onto the chilled biscuit base and use the back of a spoon, spatula or palette knife to spread in a smooth, even layer. Cover with cling film and chill in the fridge for at least 4 hours (ideally overnight) or until set. You can keep the decoration super simple by skipping the ganache and decorating with your choice of chocolates once set. Alternatively, follow the steps below.

Once the cheesecake has set, make the ganache: put the chopped chocolate into a heatproof bowl and set aside. Pour the cream into a saucepan and gently bring to a simmer. Remove from the heat and pour over the chocolate. Leave to sit for a few minutes before gently stirring until melted, glossy and smooth. Leave to cool for 10 minutes or so, so that it doesn’t melt the cheesecake when you pour it on.

Pour about ¼ of the ganache into a separate bowl and set aside to harden. Then pour the remaining  ganache over the chilled cheesecake and, using the back of a spoon, palette knife or spatula, spread in a smooth and even layer. Return to the fridge to chill for 30 minutes.

Once the reserved ganache has hardened enough to pipe, spoon into a piping bag fitted with a star or rosette nozzle and pipe swirls onto the set ganache layer. Alternatively, you can whip up some cream to firm peaks (take care not to overwhip) and pipe swirls of that instead. The piping step is completely optional - the no bake chocolate cheesecake will still look (and taste) amazing without it!

Just before serving, decorate with maltesters, crumbled flakes and chocolate curls.