Piero Antinori says: "It is a very old tradition in Tuscany to eat chestnuts. We enjoy them boiled or roasted with the new wines. In the countryside, they still make a sort of chestnut polenta called pattone. We also have several sweets or desserts made with chestnuts, such as the famous Monte Bianco, a sweetened chestnut puree mounded with whipped cream. And then you have Castagnaccio, a flat chestnut flour cake with pine nuts and rosemary. Until recently, it was sold on street corners from wide copper pans, but you can still find it in most typical Florentine trattorias." Cantinetta Antinori's version is a little crunchier than most, as flat as a cookie, and garnished with rosemary and pine nuts.
1 (12-ounce) package chestnut flour
2 cups water
5 tablespoons olive oil
1/2 cup raisins
1/2 cup pine nuts
1 tablespoon chopped rosemary
Sift chestnut flour into large bowl. Stir in enough water just until creamy (not liquid). Stir in 2 tablespoons olive oil. Let stand 30 minutes.
Mix chestnut flour batter well. Stir in raisins and pine nuts, reserving some to decorate top of cake.
Spread remaining 3 tablespoons olive oil in jellyroll pan. Heat pan and briefly saute rosemary. Pour chestnut batter onto warm oil. Sprinkle top with reserved pine nuts and raisins.
Bake at 425 degrees 25 to 30 minutes, or until edges are slightly brown and crunchy. (How crunchy or soft cake turns out depends on how much water is mixed into chestnut flour.)