London Cheesecake

*From Nigella Lawson's recipe

More pictures of this cheesecake pin-up

Ingredients:
150 g digestive biscuits
75 g unsalted butter, melted
600 g cream cheese, softened
150 g caster (gransulated) sugar
3  large eggs
3 large egg yolks
1 1/2 tablespoons vanilla extract
1 1/2 tablespoons lemon juice
Topping:
145 ml sour cream
1 tablespoon caster (granulated) sugar
1/2 teaspoon vanilla extract

Instructions:
1. Process the biscuits until they are like crumbs, then add the butter and pulse again. Line the bottom of a springform pan with this, pressing the crust in with your hands or the back of a spoon. Put into the fridge to set, and preheat the oven to 350 F (180 C).
2. Beat the cream cheese gently until it is smooth, then add the sugar. Beat in the eggs and egg yolks, then finally the vanilla and lemon juice. Put the kettle on to boil.
3. Line the outside of the chilled pan with foil so that it covers the bottom and sides in one large piece, and then do the same again and put it into a large roasting pan (the foil will protect the cheesecake fromt he water as it is cooked in the water bath).
4. Pour the cream-cheese filling into the chilled biscuit base, and then pour hot water from the boiled kettle into the roasting pan around the cheese cake pan. It should come about halfway up; don't overfill as it will be difficult to lift up the tin. Put it into the oven and cook for 50 minutes. It should feel set, but not rigid.
5. Whisk together the sour cream, sugar and vanilla for the topping and pour over the cheesecake. Put it back in the oven for a further 10 minutes.
6. Take the roasting tin out of the oven, then gingerly remove the springform pan, unwrap it and stand it on a rack to cool. When it's cooled down completely, put it in the fridge, removing it 20 minutes before eating to take the chill off. Unmould and when you cut into it, plunge a knife in hot water first.