|1||small sweet potato (about 8 ounces)|
|Butter (for the pan)|
|1||cup all-purpose flour|
|1||cup whole-wheat flour|
|1||tablespoon baking powder|
|½||teaspoon baking soda|
|⅛||teaspoon ground cloves|
|Grated rind of ½ orange|
|¾||cup plain yogurt|
|¼||cup vegetable oil|
1. Set the oven at 375 degrees.
2. Prick the sweet potato well all over. Set it in a baking dish and bake for 50 minutes or until tender. Cool, then peel and discard dark spots and eyes. Mash until smooth. Transfer ½ cup puree to a large bowl.
3. Meanwhile, in a heavy skillet, toast the walnuts over medium heat, shaking the pan constantly, for 5 minutes or until aromatic; set aside to cool. Chop coarsely.
4. Increase the oven temperature to 400. Butter 12 muffin cups.
5. In a bowl, whisk the all-purpose and whole-wheat flours, baking powder, baking soda, salt, cinnamon, cloves, and sugar to thoroughly blend them. Add the walnuts and orange rind and stir thoroughly. Make a well in the center.
6. To the sweet potato puree, add the eggs, yogurt, oil, and honey. Stir thoroughly.
7. Add the sweet potato mixture to the well. With a wooden spoon, gently fold the wet and dry ingredients together for no more than 10 to 12 seconds or just until the flour mixture is moistened. There will still be lumps in the batter but that is OK.
8. Using a ⅓-cup measure, fill each well nearly to the top.
9. Bake for 18 minutes or until the muffins are lightly browned and a toothpick inserted into the center comes out clean or with a few crumbs. Turn the pan halfway through baking.
10. Remove the muffins from the pan and transfer to a wire rack. Store leftovers in an airtight container lined with a paper towel. Holly Jennings