Lemon, lime and ginger cheesecake

Method

1. In a food processor, whizz the gingernut biscuits to fine crumbs, then add the butter and lime zest. Whizz again until everything is mixed together thoroughly. Lightly oil a 20cm diameter loose-bottomed cake tin, then evenly press all but 2 tbsp of the biscuit crumbs into the base. Chill while you make the filling. 
2. Put all the filling ingredients except the gelatine in a large mixing bowl, then beat with an electric mixer until very smooth. 
3. Put the gelatine in a medium bowl with 100ml cold water. Sit the bowl on a saucepan half filled with hot water from the kettle, then heat gently over a low heat (make sure the bowl doesn’t touch the surface of the water). Stir the gelatine until it dissolves, then stir into the filling mixture, ensuring there are no lumps. Pour the filling on top of the chilled biscuit base, then cover the tin with cling film and chill in the fridge for at least 5 hours to firm up. 
4. Remove the cheesecake from the tin, then sprinkle over the reserved biscuits and extra lime zest to serve.