Chocolate and Chestnut Cake

This flour-less cake is one of the first recipes I turn to when fresh chestnuts come into season. It really does have to be freshly cooked and sieved chestnut, not tinned purée, but the delicate cake that emerges from the oven is-more than ample reward for all the extra work.

See the recipe for Chestnut and Walnut Pie for method of cooking the chestnuts, but rub them through a sieve rather than chop them.