Rinse beans. In a 4-1/2-quart Dutch oven combine beans and cold water. Bring to boiling; reduce heat. Simmer, uncovered, for 2 minutes. Remove from heat. Cover and let stand for 1 hour. (Or, skip boiling the water and soak the beans overnight in a covered pan.) Drain and rinse beans.
In the same pan combine beans and 8 cups fresh water. Bring to boiling; reduce heat. Cover and simmer about 1-1/4 hours or until tender, stirring occasionally. Drain beans, reserving liquid. In the same pan cook the 6 ounces pancetta or bacon over medium heat until slightly crisp. Add onion to bacon and drippings; cook and stir until tender. Add brown sugar. Cook and stir until sugar dissolves. Stir in molasses, maple syrup, Worcestershire sauce, dry mustard, salt, and pepper. Add drained beans and 1 cup of the reserved bean liquid. If desired, transfer to a bean pot.
Cover and bake in a 300 degree F. oven for 2-1/4 to 2-1/2 hours or to desired consistency, stirring occasionally. If necessary, add additional reserved bean liquid. If desired, sprinkle with additional cooked pancetta or bacon before serving. Makes 10 to 12 servings.