The secret to the perfect sticky bun is butter. Not just for spreading on each 4-inch tall, caramel-lacquered sweet roll, sprinkled with fat pecans but as a primary ingredient in the dough. The Chacko's sticky bun is baked and sold at the tiny bakery only on Thursday, Friday and Saturday mornings. "We did that to help build an intense desire for our patrons to come in for them on those days," says David Finn, who owns Chacko's with his wife, Rachel. "It makes our sticky bun more special because you can't come in and get it every day." But even on those three days, the buns move fast — they're sometimes gone only a couple of hours after baker Joe Gotshall puts out his first trays at 7 a.m. One angry patron stormed out of the place on a Friday morning when the pastry case held just a healthy oat-bran muffin. (When one has been craving a softball-sized sticky bun, a bran muffin is never the answer.) "If you call ahead," Finn says, "we'll set a few aside for you."