From the front, this bakery looks handsome and unassuming. Walk around the back at night, though, and you’ll stumble on a sight that practically defines Martha Vineyard summers: dozens of customers lining up to buy freshly prepared fritters and donuts through the back door between a dumpster and an alley. This back-door business has a long history: The location has been a bakery since Walmsley’s Bakery opened there in 1948. While there are legends that Walmsley employees threw unused donuts out the back door, its first official use came after the shop changed…
