White chocolate and limoncello cheesecake

Method

1. In a food processor, whizz the biscuits with a good pinch of salt to the texture of breadcrumbs. With the motor still running, add the butter to combine. (Or put the biscuits in a freezer bag and bash to crumbs with a rolling pin. Tip into a bowl, then mix in the melted butter.)
2. Firmly press the biscuit mixture into the base and up the sides of the prepared tin, then chill for 30 minutes.
3. Heat the oven to 170°C/150°C fan/gas 3½. Put the white chocolate in a heatproof bowl over a pan of barely simmering water (don’t let the bowl touch the water). Stir occasionally with a metal spoon until melted, then set aside.
4. Put the cream cheese, sugar, soured cream, limoncello and lemon zest and juice in a large mixing bowl. Using an electric mixer, beat until well combined and smooth. In a separate bowl, beat the cornflour and eggs until smooth, then beat into the cream cheese mixture. Stir in the melted chocolate.
5. Pour the filling into the chilled biscuit base, then put the cake tin on a baking tray and bake for 50-60 minutes until the top is firm at the edges but the centre still has a slight wobble. Turn off the oven and leave to cool inside (leave the door slightly ajar) for 2-3 hours.
6. Put the cheesecake in the fridge and leave to set for 6 hours or overnight. An hour before serving, stir the lemon curd to loosen, then spoon over the cheesecake and chill for another hour before serving.