Spiced Sweet Potato Muffins

Directions

1. In a large bowl, combine the flour, 1 cup sugar, orange zest, baking powder, ginger, salt and baking soda. In a small bowl, combine eggs and sweet potatoes; stir into dry ingredients just until moistened.
2. Fill greased or paper-lined muffin cups two-thirds full. Combine cinnamon and remaining sugar; sprinkle over batter.
3. Bake at 400° for 16-20 minutes or until a toothpick inserted in the center comes out clean. Cool for 5 minutes before removing from pans to wire racks.
4. In a small bowl, combine the ginger butter ingredients. Serve with warm muffins.