Position the rack in the center of the oven and preheat to 400 degrees. Lightly grease or line with paper baking cups 18 (2-3/4-inch) muffin cups.
In a mixing bowl, combine the first seven ingredients. Make a well in the center. In a separate mixing bowl, combine the egg, oil, molasses, buttermilk and pineapple with juice. Pour into well; mix until dry ingredients are well moistened. Stir in nuts, dates or raisins.
Spoon the batter into the prepared muffin cups, filling each about three-quarters full.
Bake at 400 degrees for 15 or 20 minutes, or until the tops turn a light golden and a cake tester or wooden toothpick inserted into the center of a muffin comes out clean. Cool in the pan on a wire rack for 5 to 7 minutes. Serve warm, or invert onto the rack to cool completely.
Serving suggestion: Serve with jam or preserves.