Bake the potatoes at 425 degrees (F) for 1 hour, then turn the heat down to 350 (F) [see Note]. Scoop out the potato flesh and place in the bowl of a food processor; puree until smooth. In a large mixer bowl, combine the sweet potato puree, granulated sugar, eggs, 4 Tablespoons of the butter, orange rind, ground ginger, salt, pepper, and crystallized ginger. Blend well and spread in a greased 13x9-inch flat baking dish. In a small bowl, combine the flour, nuts, remaining 6 Tablespoons of butter and the brown sugar. Sprinkle ovver the potato mixture and bake for 1 hour, or until the top is browned and puffs slightly. [Note: If using a glass dish, reduce baking temperature to 350 degrees (F).] From Heartland, by Marcia Adams, ISBN 0-517-57533-7, 1991