Reading this post from Jeremy at Frost Street, I felt the urge to do some cupboard “cleaning”. As usual I threw off way less than I could have, but found a long forgotten bag of chestnut flour I had brought back from Italy last winter. Chestnuts, like acorns, are one food item that used to be associated with poverty. They were used as a source of carbohydrates from those who could not buy flour or who lived in remote valleys, especially in the winter months. In some parts of Italy the importance of chestnut woods as food source went beyond mere subsistence: it was such that it influenced the cuisine of these areas. Although a few examples exist throughout Italy, where this is most evident is certainly the northern mountainous part of Tuscany bordering Liguria. Here bread, polenta and sweets were, and in part still are, made using chestnut flour. The most famous of these dishes is certainly castagnaccio a chestnut flour cake enriched by nuts and, in its richer versions, a few other ingredients. I hadn't had castagniaccio for ages, so the recipe for my, let's call it, cupboard-archaeology treasure was decided.
Castagnaccio, although eaten as a sweet, is probably not exactly what would fall in most people's definition of one. It hardly contains any sugar except that from the naturally sweet chestnuts. Add nuts, rosemary and olive oil to that and you can imagine how the taste might not be everyone's cup of tea. The classic, basic castagnaccio, tastes slightly sweet with the slight bitter note of rosemary. It is simply made by mixing together a slightly runny batter out of chestnut flour, some oil and water (plus one or two pinches of salt). This is then poured in a rather wide cake or pie form, so the batter isn't higher than 2 cm. On top come pine nuts, rosemary and a little olive oil, and then the cake goes in the oven, pre-heated at 180C (350F), for about 30-40 minutes. The top is then slightly crunchy while the rest of the cake remains rather moist. I actually prefer to spread my batter in a larger form so that it stays thinner, more like 1 cm, for more top crust. There's no oven rise in this cake, the baking is only needed to cook the chestnut batter.
Topping can be enhanced quite a bit. Ingredients that can enrich castagnaccio are raisins, walnuts, a little fennel seeds and orange peel. All these are not uncommon but probably represent a social and not only culinary step up from the humble origins of the dish. I decided for once to try a rich version of castagnaccio, which uses all of the above ingredients, apart fennel, has a bit of sugar and substitutes milk for the water in the batter. The result is pleasant, the orange peel adding a nice contrast and the amount of topping was abundant but not overwhelming. The only thing I'll probably change next time is the use of the milk in the batter. When you use water the castagnaccio turns a beautiful dark brown colour and has a crunchier top crust. Using only milk the crunch is almost gone, so I'll probably try half milk and half water next time.
Castagnaccio ricco (rich castagnaccio)
Serves 4 to 6
250 g chestnut flour
about 400 ml whole milk, lukewarm (or half milk half water)
2 pinches of salt
50 g raisins, plumped up for about 30 minutes with some warm water
50 g pine nuts
a scarce handful of walnuts, chopped
a scant tablespoon of sugar
the needles of a small FRESH rosemary sprig
2 tablespoons of extra virgin olive oil
the peel of about 1/4 of an orange, julienned
Pre-heat your oven to 180C. Sieve the flour, and add enough water to form a slightly thin batter, more or less like crepe batter, taking care to avoid lumps. Add the salt and sugar and mix. Pour in an oiled (with olive oil) 25-30 cm wide cake or pie form, depending on how thin you want your castagniaccio. Sprinkle raisins, pine nuts, walnuts and orange peel on top. Slide in the warm oven and bake for about 35 minutes. Remove from the oven, let cool and cut into wedges.
Eat accompanied by a glass of Vin Santo and maybe a little fresh ricotta on the side.