Lightly oil a 20 cm loose-bottomed tin and line the base with baking paper.
Blitz the cookies and the cocoa in a food processor until you get a fine crumble. Transfer to a bowl, add the melted butter, combine. Tip the mixture to the tin, pressing it into the base evenly with the back of the spoon. Put the tin to the fridge for minimum 30 minutes.
Make the filling: put the cream cheese, mascarpone and icing sugar into a mixing bowl, then beat with an electric hand mixer until smooth. Add the double cream and orange zest and beat again until smooth and very thick (a spoon should be able to stand upright in the mixture.).
Spoon the cheese filling on top of the crust and smooth over evenly with the back of a spoon. Return the tin to the fridge ( covered with foil) and chill for at least 6 hours, overnight if possible.
When the cheese filling has hardened start making the jelly. Soak the gelatine in a bowl of water for 10-15 minutes.
Add 4 Tbsp of prosecco and the sugar to a small pan. Gently heat it up and stir for a few minutes until reduced and syrupy. Turn off the heat.
Squeeze the excess water from the gelatine leaves and add to the pan, stirring until dissolved. Stir in the Aperol and orange juice, then pour the mixture into a jug and put it in the fridge for about 45 minutes until the jelly is just about to set (it should be still liquid).
Add the prosecco, whisking into the jelly gently. Skim off any foam that rises to the surface. Put it back to the fridge for 10 minutes or so until the jelly has thickened, then pour it over the cheesecake, letting it spread out evenly.
Chill the cake for 4-6 hours before carefully removing the side of the tin.