This baked cheesecake is exceptionally creamy. Cheesecakes are prone to cracking; usually this means they have been baked at too high a temperature. The mixture should not be overbeaten as this is likely to lead to the mixture sinking in the oven as the extra volume deflates.
100g butter, melted
300g wheatmeal biscuits
500g cream cheese, at room temperature
200g castor sugar
1 tbsp cornflour
2 tbsp lemon juice
few drops pure vanilla, or vanilla extract to taste
pinch of salt
2 cups sour cream
Preheat oven to 180ºC. Brush the base and sides of a 22cm x 6cm deep springform tin with a little of the melted butter. Remove the base from the tin.
Cut a round of baking paper to fit the base of the tin, brush the paper with a little butter and set aside.
Tear off an 80cm sheet of foil and double it over so it measures 40cm in length. Lay the foil over the base of the tin, then put the buttered round of paper on top. Sit the springform tin over the base and lock the sides into place, leaving excess foil outside the tin. Draw up the excess foil around the tin and fold the top out of the way. You now have a watertight container.
Crush the biscuits in a food processor. Add the remaining butter and process. Press the crumb mixture into the base of the tin, tapping firmly with the base of a glass tumbler or similar as you go.
Beat the cream cheese and sugar in an electric mixer until smooth. Beat in the cornflour, then add the eggs, 1 at a time, beating each time just until smooth. Add the lemon juice, vanilla and salt. Add the sour cream and beat briefly to combine. Pour the batter into the tin and stand the tin in a large baking dish. Pour boiling water into the dish to come halfway up the sides of the tin.
Bake for 50 minutes, then turn off the oven but do not open the door for a further hour.
Lift the tin from the water bath and flatten the foil away from the sides just in case there is any water trapped inside. Cool completely in the tin on a wire rack and refrigerate for several hours or overnight before serving.