There is no doubt about it, anything with chestnuts in it, even if they come vacuum-packed or canned and are perennially available, is so right for this time of year. The chestnuts are present, in the form of a gritty, grainy sweetened purée: some to add to the biscuit base; some to fold through the plain cheesecake filling before baking; and yet more — well, it is Christmas — to drip in a thick syrup over the cake when served. And yet, you know, the chestnuttiness is not blaring: there is something undeniably festive about this, but not in a full-on, party hat kind of a way. As with all cheesecakes, you need to bake this the day before you want to serve it. For US cup measures, use the toggle at the top of the ingredients list.