March 19 is the feast of St. Joseph, and in Naples it is zeppole day. The custom was pushed along by a baker named Pasquale Pintauro in the early 1800s, and the first written recipe appeared in an 1837 Neapolitan cookbook. In Sicily, where Joseph is patron saint, the same day brings sfingi. In Italy it is also Father's Day.
The original zeppola is fried. The Rhode Island version, where one in five residents claims Italian ancestry, became a baked choux ring filled with rum or vanilla cream, dusted with powdered sugar and finished with a maraschino cherry. One Providence baker estimated 25,000 a spring, 500 to 1,000 a day in the week before the holiday, "and after that you couldn't give them away."
A fair warning about this trail. The pastry shops that own March 19 are mostly not donut shops, so they appear here as non-listings. The directory's own Italian-family bakeries sit beside them for their roots and their donut cases, not because we could confirm a zeppola on the counter. Call first.