Wash and dry sweet potato. Wrap well in foil and roast in oven or toaster oven for 60-75 minutes at 400F. It should be quite soft and easily pricked by a fork. Once cool, peel and mash sweet potato - yields roughly 1 cup.
Mix topping ingredients together with fork or fingers, until it is a crumbly mixture. Wrap airtight and place in fridge until ready to use. This can also be done ahead of time.
Preheat oven to 350F. In large bowl, combine flour, flax, cinnamon, nutmeg, baking soda, baking powder, and salt.
In another large bowl, combine eggs, sugars, sweet potato, oil, vanilla, and water.
Gently fold wet ingredients into the dry ingredients, just until completely moistened. Do not over stir.
Spoon batter into lined muffin pan, filling to the tops. Sprinkle crumb topping generously over muffins. Bake for 19-21 min, or until toothpick inserted in centers emerges almost clean. Carefully test to make sure muffins are not over baked.
Cool muffins in pan about 15 minutes before remove onto wire rack to cool completely. If desired, combine glaze ingredients and drizzle over cooled muffins.
Notes
Mash the sweet potato until smooth. A few small bits are fine, but a mostly smooth mash ensures even texture in every bite.
I sometimes sub out 3/4 cup of all-purpose flour with whole wheat flour, for extra nutrients, fiber, and earthier flavors.
Ground flaxseed meal helps muffins retain moisture, giving them a rich, tender crumb. You can use applesauce or mashed banana in place of ground flax seed meal, though there may be a slight difference in texture.
Don’t overmix the batter. Stir just until the dry ingredients are moistened to keep the muffins light and tender.
Option: For a bread loaf instead of muffins, pour batter into a greased/floured 9x5 inch loaf pan. Sprinkle topping over loaf. Bake at 350F for 50-55 minutes or until toothpick inserted in center emerges with a few tender crumbs.
If you enjoyed this recipe, please come back and give it a rating. We ❤️ hearing from you! Join our Free Recipe Club and get our newest, best recipes each week!