Heat oven to 160C. Butter a cake tin. Mix together the crushed biscuits and the butter into a paste, line the bottom of a cake tin.

Bake the base for 10 min in the oven. Cool. Meanwhile beat the egg whites in a metal bowl until soft peaks form (1-2 minutes). Set aside.

With an electric mixer, mix Butter, cream cheese and egg yoks. Beat at med speed, until smooth and creamy. Add sugar, baking powder, cornflour and lemon juice. Mix well.

By hand, fold in the beaten egg whites. Spoon into cooled baking pan. Bake for 60-80 minutes.

Switch of the oven when the cake is golden brown after 60 or 70 minutes and place a wooden spoon in the door. (The cake will fall in the centre and crack). Cool for 15 minutes.

Take a knife and loosen the cakes edges from the side of the tin. Cook completely in the fridge for 4 hours or overnight.

Just before serving: cream together the sour cream, sugar and vanilla. Spoon over the cracked surface of the cheesecake. Take 1/2 teaspoons of the cherry jam and arrange neatly around the cake for decoration and the cherry taste.