London Cheesecake
This is one of the best sort of recipes — a family hand-me-down. My paternal grandmother instructed me in the art of adding the final layer of sour cream, sugar and vanilla towards the end of the cooking time: and it's true, it does finish it off wonderfully.
I cannot tell you how much the velvety smoothness is enhanced by cooking the cheesecake in the water bath. It's not hard, though you really must wrap the tin twice in extra-strength tin foil. Once you've tried it this way, you won't even consider cooking it any other.
For the Base
150 grams digestive biscuits
75 grams unsalted butter (melted or very soft)
600 grams cream cheese
150 grams caster sugar
3 large eggs
3 large egg yolks
1½ tablespoons vanilla extract
1½ tablespoons fresh lemon juice
For the Topping
145 millilitres sour cream
1 tablespoon caster sugar
½ teaspoon vanilla extract
For the Base
10 sheets graham crackers
5 tablespoons unsalted butter (melted or very soft)
2½ cups cream cheese
¾ cup superfine sugar
3 large eggs
3 large egg yolks
1½ tablespoons vanilla extract
1½ tablespoons fresh lemon juice
For the Topping
½ cup sour cream
1 tablespoon superfine sugar
½ teaspoon vanilla extract
Method
Process the biscuits until they are like crumbs, then add the butter and pulse again. Line the bottom of a 20cm / 8 inch springform tin, pressing the biscuits in with your hands or the back of a spoon. Put the tin in the fridge to set, and preheat the oven to 180ºC/160ºC Fan/gas mark 4/350ºF.
Beat the cream cheese gently until it's smooth, then add the sugar. Beat in the eggs and egg yolks, then finally the vanilla and lemon juice. Put the kettle on.
Line the outside of the chilled tin with strong foil so that it covers the bottom and sides in one large piece, and then do the same again and put it into a roasting dish. This will protect the cheesecake from the water as it is cooked in its water bath.
Pour the cream-cheese filling into the chilled biscuit base, and then pour hot water from the recently boiled kettle into the roasting tin around the cheesecake. 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 rigidly so: you just need to feel confident that when you pour the sour cream over, it will sit on the surface and not sink in. 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.
Take the roasting tin out of the oven, then gingerly remove the Springform, 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.
Additional Information
For vegetarians check that the cream cheese is a brand that does not contain rennet.
MAKE AHEAD / STORE: The cheesecake can be made up to 2 days ahead. Cool as directed in the recipe then cover the top of the springform pan and refrigerate until needed. Remove from the fridge 20 minutes before serving and serve as directed in the recipe. The cheesecake will keep in the fridge for up to 5 days in total from the day it is made. Leftovers should be stored in the fridge, loosely covered.
