• 4 tablespoons water
• 15 g/½ oz powdered gelatine
• 3 large eggs
• 100 g/4 oz castor sugar
• juice and finely grated rind of 2 lemons
• 450 g/1 lb cream cheese
• 1 170 - g/6- fl oz carton double cream

For the Crumb Base

• 8 digestive biscuits
• 1 level tablespoon castor sugar
• 50 g/2 oz butter

Measure the water into a saucepan, sprinkle in the gelatine and set aside to soak for 5 minutes. Stir over low heat until the gelatine has dissolved; draw off the heat ready to use.

Separate the eggs, placing the yolks in one basin and the whites in a second larger basin. Add the sugar, lemon juice and finely grated lemon rind to the egg yolks. Place the basin over a saucepan half filled with simmering water and whisk until the mixture is frothy and light in colour. Remove from the heat and whisk in the dissolved gelatine.

Blend the cream cheese until smooth and then gradually whisk in the gelatine and egg mixture. This is easiest done on a machine or with a hand mixer if you have one. Beat the mixture well until thick and light; by now it will be almost at setting point. Lightly whip the cream and stiffly beat the egg whites. Fold both into the cheese mixture gently but thoroughly. Pour into a 20 - cm (8 - in) round deep cake tin, lined on the base with a circle of greaseproof paper.

Crush the digestive biscuits and mix with the sugar. Melt the butter and stir in the crumbs with a fork. Spoon over the top of the cheese-cake mixture and chill until firm.

When ready to serve, loosen around the top and turn the cheesecake out on to a plate. The biscuit crumb topping will now be on the base. Serve with cream or fresh fruit.