Ingredients: The base:
- 250g digestive biscuits
- 50g soft butter
- 1 heaped tablespoon sweetened chestnut puree
- 500g cream cheese
- 125g caster sugar
- 3 large eggs
- 3 large egg yolks
- 175ml sour cream
- 1 tsp lime juice
- 1 tsp vanilla extract
- 1 - 2 tbsp rum
- 350g sweetened chestnut puree
- 80ml water
- 60ml rum
- 1 tbsp sweetened chestnut puree
- 50g caster sugar
- 15g butter
- Preheat the oven to 180°C/gas mark 4/350°F, and put the kettle on to boil.
- For the base, process the biscuits, butter and heaped tablespoon chestnut purée until like fine crumbs. Press the mixture into the bottom of a 23cm / 9inch springform cake tin and place in the fridge while you make the filling.
- Beat the cream cheese until smooth and add the sugar. Add the eggs and egg yolks, beating them in one by one until they are incorporated into the cream cheese and sugar. Pour in the sour cream, lime juice, vanilla extract and rum, and beat again until smooth and creamy. Finally fold in the sweetened chestnut purée. It may not be a smooth mixture, but smooth cream cheese with grainy streaks of chestnut is still the right consistency.
- Line the outside of the springform tin containing the biscuit base with a good wrapping of clingfilm, so that the whole of the bottom and sides are enveloped in cling.
- Do the same with foil, covering the layer of clingfilm to make a very watertight casing.
- Stand the springform, thus covered, in a roasting tin and pour in the chestnut filling. Once that’s done, pour water from a recently boiled kettle into the roasting tin to come about 3cm / 1¼ inches up the side of the cake tin (the cling will make it bob up and down a bit) and place in the oven to cook for an hour.
- When the cheesecake’s ready it should be just set on top with a hint of wobble underneath; it certainly carries on cooking as it cools. Take the cheesecake out of the roasting tin, take off the foil and clingfilm wrapping and let the cheesecake cool on a rack.
- Refrigerate overnight before unmoulding and leaving it to get back to room temperature.
- If you need to unmould it long before you want to eat it, then just sit it on its serving plate in the fridge until about 20–30 minutes before you want to eat it. Alternatively, you can take it out of the fridge and leave for 20 minutes before serving.
- You can make the syrup in advance but do not pour over until the actual point of serving. You just put all of the syrup ingredients into a saucepan and melt together. Let the syrup boil until thickened slightly, then cool to just warmish (or even room temperature) before criss-crossing the top of the cheesecake with it.