1. Bash biscuits with a rolling pin or mince in a food processor into crumbs and mix with the melted butter.

2. Line the a 9 cake tin with greaseproof paper,  press the crumb mixture into it and chill for one hour.

3. Now pre-heat oven to 260C or gas Mark 8.

4. The rest of the recipe works best if done in a processor but can be done by hand also.

5. Beat cheese until soft, add sugar and beat again until it is all dissolved.

6. Add eggs one at a time, making sure each egg is mixed in well before adding the next.

7. Add cream, sour cream, vanilla extract, lemon peel and juice and mix well.

8. Pour over the biscuit base and bake in the hot oven for 10 mins only.

9. After 10 mins, open the door of the oven wide, turn down the tempreture to just under 100C or gas mark 1 and wait for the tempreture to drop. (wafting the open door will help this!)

10. When oven has cooled, continue to cook for 1-1.25 hour or so. To test if it is done tap on the side of the tin, the outside should be firm but the centre should wobble

11. When you think it is ready, turn off the oven, open the oven door, keep it ajar and leave the cake in the cooling oven for a few hours or overnight is best. Do not take this cake out of the oven while it is cooling, long slow cooling is best otherwise you will get cracking in the cake.

12. When cake is cool, refridgerate for a minimum of 4 hours but preferably for 24 hours.  Cake should shrink back from the edge making it easy to take out.