A cheesecake is fragile and not a cake that can be turned out of the baking tin. Bake it in a tin that opens from the side with a spring clip; most specialist cook-shops sell them. For the best flavour and texture, allow the baked cheesecake to stand for 24 hours before serving.
Melt the butter in a small saucepan and draw off the heat. Crush the biscuits to crumbs and, using a fork, stir into the butter. Blend the mixture well, then spoon into the base of a buttered 20-cm (8-in)