Preheat the oven 150 C.  Grease a round 22 cm spring form cake pan and line the base with baking paper.
Place the biscuits in a food processor and blitz until fine crumbs.
Pour in the melted butter and pulse until just combined.
Press the biscuits in an even layer in the base and sides of the cake pan.

Clean out the food processor and then add the cream cheese, sugar, eggs and lemon, process until the mixture is smooth and creamy.
Pour into the biscuit base and bake for around 40 minutes until there is just a slight wobble left in the centre of the filling.
Meanwhile mix the sour cream, sugar and vanilla, pour over the cheese cake and bake for 10-15 minutes until the topping starts to set.
Allow to cool for half an hour and then gently run a knife around the outside of the cheesecake to lift the crumbs away from the tin.
Chill for at least 8 hours before serving.