Cheesecake with sultanas

• 8 digestive biscuits
• 2 oz (50 g) butter

Heat the oven to 325°F (160°C) or gas no. 3. Finely crush the biscuits. Melt the butter in a saucepan over low heat and stir in the crumbs with a fork. Spoon biscuit mixture over the base of a greased 8 inch (20 cm<