Preheat oven to 400°F. Line 12 large muffin cups with foil muffin papers.
Puree potato in processor. Measure 1 cup puree and transfer to bowl. Mix in eggs, then milk, molasses and butter. Add all remaining ingredients and stir until just mixed. Divide batter among muffin cups. Bake until springy to touch and tester inserted into center comes out with just a few moist crumbs, about 25 minutes. Transfer to rack. Serve warm or at room temperature.