Chestnut flour cake

Method

1. Combine the chestnut flour, sugar (if using) and salt in a bowl. Add the water, bit by bit, stirring with a wooden spoon or whisk to avoid lumps. You are looking for a batter that will run off the back of a spoon, much like pancake batter. Depending on the quality of the flour, you may need a little more or a little less water than called for to obtain this consistency.
2. When smooth, add 2 tablespoons of olive oil and the orange zest to the batter and mix it in. Allow the mixture to rest at least 30 minutes (or overnight).
3. Preheat the oven to 180ºC and line a 30 cm round pizza tray with baking paper. Alternatively, you can use a rectangular baking tray of similar dimensions.
4. Soak the sultanas, nuts and rosemary in cold water for 15 minutes. Drain.
5. Pour the batter into the round pizza tray (or rectangular baking tray). The batter should be not much more than 1 cm high. Evenly scatter over the sultanas and nuts, the rosemary leaves and the rest of the olive oil.
6. Bake in the oven for about 30 minutes, or until you begin to see little cracks appear all over the top. Do not over-bake or it will become very dry. Let it cool in the pan, then cut it into wedges.
7. To make the ricotta cream, whisk the ricotta, sugar and lemon zest together in a bowl. Chill until needed.
8. Serve the castagnaccio on its own or with a dollop of ricotta cream. This is best on the day it is baked, so share it around. However, it does keep for a day in an airtight container at room temperature. It’s best not to store it in the refrigerator as it tends to get hard and rubbery when chilled.