Castagnaccio has been made since the sixteenth century, and no wonder: it is delicious, economical, and simple to make. The fresh chestnut flour’s natural sweetness shines, accompanied only by raisins, a sprinkle of pine nuts or walnuts, and a few fresh rosemary leaves.

Serves 10.

¾ cup raisins (organic Sultanas, Thompson, Black Corinth, Muscat, or a mixture)

1½ cups plus ⅓ cup (200 grams total) Italian chestnut flour, plus more if needed

1⅔ cups (400 grams) warm water, plus more if needed

⅓ cup pine nuts or walnut pieces (or a mixture)

1 tablespoon fresh rosemary leaves

1. Preheat the oven to 400°F. Steep the raisins in hot water until they rehydrate, about 5 minutes. Drain.
2. Sift the chestnut flour into a mixing bowl and add the warm water, whisking until your batter is smooth, completely lump-free, and the consistency of a thin pancake batter. Test by sprinkling a few raisins onto the batter and observe: if all the raisins sink, the batter is a bit too thin; if they all float, it is too thick. Adjust by adding a teaspoon of chestnut flour or water until your batter allows some raisins to submerge while others rest on top.
3. Pour the batter into a ceramic or glass baking dish. (If you use a metal baking tin, first line it with parchment paper.) Castagnaccio should be ¾-inch thick (and sometimes even thinner), so check the depth of the batter and change your baking dish if necessary. Sprinkle on the nuts and the rest of the raisins. Strew the rosemary over the surface.
4. Bake in the center of your oven for approximately 30 minutes, but begin checking for doneness at 20 minutes. Castagnaccio is ready when the surface develops its signature cracks, the nuts turn golden, and it is fragrant.

Chef’s Note: It’s best to buy chestnut flour from Italy in Sept and Oct when it is at its sweetest and freshest. Then store it in the freezer for rewarding castagnacci and necci and chestnut crepes (all in the cookbook, too!) all year long.