In a large nonreactive saucepan, combine the potatoes, cider, brown sugar, 6 tablespoons of the butter and the cinnamon stick. Bring to a boil over moderate heat. Reduce the heat to a simmer, partially cover and cook, stirring occasionally, until the potatoes are very tender, about 45 minutes.
Let cool slightly, remove the cinnamon stick, and pass the potatoes through the medium disk of a food mill or puree in batches in a food processor. Transfer to an overproof serving dish. The potatoes can be prepared to this point up to 4 days ahead. Cover tightly and refrigerate. Return to room temperature before proceeding.
Preheat the oven to 325F. Dot the potatoes with the remaining 2 tablespoons of butter, cover with foil and bake, stirring once or twice, for about 20 minutes, until steaming. Remove the foil and bake for 5 minutes longer.
From: Michael McLaughlin in Food & Wine 11/93 Submitted By SUSAN ANDERSON On FRI, 11-05-93 (23:02)