Grease the base and side of a 28 cm (11¼ inch) spring-form cake tin. Preheat the oven to 180°C (350°F/Gas 4). Combine the crushed biscuits, sugar and melted butter, then spread this mixture over the base, pressing it down well with the bottom of a glass. Place in the oven and bake for 15 minutes. Take the crust out of the oven and increase the temperature to 230°C (450°F/Gas 8).
The Cheese Filling
Using an electric mixer or food processor, combine the filling ingredients, in the order they are listed, until smooth. Pour over the crust.
Bake for 10 minutes. Without opening the oven, lower the temperature to 100°C (200°F/Gas ½) and cook for another 50 minutes. The filling should still be a little wobbly in the centre. Turn the oven off and let the cheesecake rest inside for 2 hours, then let it cool outside of the oven and refrigerate for at least 4 hours before serving.