Method:

Whizz the biscuits to crumbs using a food processor, or tip into a food bag and crush with a rolling pin. Mix with the melted butter (or melted butter Alternative), then press into the bases of a 20cm Springform cake tin. Chill in the fridge until needed.

Put the cream cheese, icing sugar and lime juice in the bowl, and then using an electric mixer, mix until smooth.  Tip in the double cream and continue beating until completely combined and smooth.

Spoon the cream mixture onto the biscuit base, working from the edges inwards and making sure that there are no air bubbles.  Smooth the top of the cheesecake down with the back of a dessert spoon.  Leave to set in the fridge. 

Melt the dark chocolate in a bowl with the oil, and mix until uniformed.  Pour into piping bay and drizzle the top of your cheesecake in a random design