Neccio (pl. necci), also called niccio, ciaccio, or cian, is a galette made with chestnut flour, typical of some mountain zones of Tuscany and Emilia, in Italy, and on the island of Corsica, in France.
Today people tend to consider neccio a dessert, but peasants once used to eat it with savory food.
The Italian government has declared neccio a Prodotto agroalimentare tradizionale ("traditional Italian regional food") of Tuscany.
Neccio is typical of Pescia and the Pistoia Mountains, the Lucchesia, the upper Versilia, the Garfagnana, the Frignano and the upper Reno valley. It is also prepared on the French island of Corsica.
In Garfagnana, a region of Tuscany, "neccio" is a term that designates the chestnut nut and its derivatives.
Other names used for neccio are ciaccio (in Versilia, upper Garfagnana and Frignano), cian (in Lunigiana), caccìn (in the province of La Spezia), panèlla (Sestri Levante and surroundings), castagnaccio or patolla (having a more consistent dough) or nicciu (in Corsica).
The dough is made with chestnut flour, water, and a little salt. In the Pistoia area, chestnut flour is stored in special chestnut wood containers called bigonce or bugni, or in wooden crates called arconi, from which the flour flakes are taken and strained through a sieve, then chopped by hand. Cooking is difficult and requires both a considerable expertise and either special discs called testi, made of fire-quenched sandstone, pre-heated on the fireplace fire, or iron discs with long handles, named ferri or forme, which must be placed on the surface of the wood stove. Today the testi are more used on the Bolognese side of the Apennines, while in the Pistoia mountains the most-used tools are the ferri.
Cooking with testi is particularly complex. Chestnut leaves are harvested in summer during waning moon and left to soak in lukewarm water. They prevent the necci from sticking to the testo and transmit their aroma and taste to them. After the testi have been heated in the fireplace, three to four leaves are laid on a testo, then a ladle of dough is put on them, then three to four more leaves and another hot testo, and so on, until a pile (named "castellina") is formed. The testi's pile is framed by an iron holder tool which stabilizes it. Usually one would pile up one of more rows of testi for 10-20 necci per row, with decreasing diameter from bottom to top. After two to three minutes the necci are ready and the pile is dismounted. 
After cooking, the necci are generally stuffed with ricotta cheese (sometimes enriched with dark chocolate chips and/or candied fruit) and rolled up to take the shape of a cannolo.
Neccio can be consumed in these ways: