Made in eastern Sicily and on Puglia's Salentine peninsula, mustazzoli are said to date from the ancient Romans, who made mustaceum, biscuits flavoured with grape must for weddings.
These days they are made in various forms, of flour, honey (but sometimes too with mosto cotto), almonds, and cinnamon, with a whole range of other possible additions and flavours, including chocolate (the most popular) candied fruit, and so on. Some are glazed with chocolate as well.
Made throughout southern Italy, they (naturally!) have a dozen other names and spellings, among them: bisquetti, castagnette, castagnole, mostacciuoli, mastazzola, mustaccioli, mustazzueli, 'nnasprati, mustazzòli,'nnsparati, pisquetti, scagliòzzi, scàiezzuli, scajèzzuli and zozzi.