Grease and line the base and sides of a round 20cm springform cake tin.

In a food processor, process biscuits to a fine crumb, add cocoa and process until combined. Add melted butter and process until combined and mixture resembles wet sand. 

Tip mixture into prepared cake tin and press evenly to the base and sides of the tin, using a flat-bottomed cup can help to press the mixture in evenly. 

Place in the refrigerator for 30 minutes before filling.  

To make the filling, heat the lime juice in a microwave or small saucepan until hot. 

Pour into a small bowl if heated in a saucepan, sprinkle over the gelatine, whisk until dissolved. Set aside to cool a little. If it begins to solidify, reheat gently for a few seconds at a time and stir. 

In a separate bowl, beat cream until soft peaks form, set aside. 

In another bowl, using an electric mixer, beat cream cheese until smooth. Add condensed milk, vanilla and sugar, beat well. 

Add gelatine mixture and lime zest and beat until combined. If using green food colouring, add a couple of drops and beat until combined. Fold through whipped cream. 

Pour into prepared base, smooth out, allowing at least half a centimetre at the top for the ganache. 

Refrigerate overnight or at least 8 hours. 

To make ganache topping, combine Koko Black Dotties | White Chocolate and cream and melt over a double boiler, or in the microwave in short 20 second bursts, stirring each time until chocolate is melted and combined with the cream. 

Set aside for 10 minutes to cool slightly, and then pour gently over the top of the cheesecake filling. 

Refrigerate for a further half an hour until set.