This traditional Italian chestnut cake is prepared with chestnut flour, olive oil, rosemary, raisins, and (occasionally) pine nuts. The recipe does not call for any other type of flour or sugar, making this cake a gluten-free and sugar-free delicacy.
Some varieties may use other dried fruits, but the traditional version only includes raisins. All the ingredients used in castagnaccio create a dense, not overly sweet cake with a crunchy exterior and chewy interior. Originally, the cake was created as a poor man's dessert and was prepared seasonally, most commonly in winter months, when chestnuts are at their peak.