¾-1 pound sweet potatoes (2 small or I medium)
1½ cups buttermilk
1 cup white whole-wheat flour
1 cup all-purpose flour
1 teaspoon baking powder
½ teaspoon baking soda
½ teaspoon table salt
½ teaspoon nutmeg, preferably freshly ground
¼ teaspoon ground allspice
¼ cup (½ stick) butter, room temperature
¼ cup sugar
¼ cup packed dark brown sugar
1 large egg
2 teaspoons vanilla extract
½ cup chopped crystallized ginger
Heat the oven to 400 degrees. Line a 12-cup muffin pan with paper cupcake liners or lightly spray the cups with cooking spray.
Prick the sweet potatoes several places with a knife. Microwave on high (or on the baked potato setting) until tender, about 10 minutes. Let cool, then peel and, in a medium bowl, mash with a fork. You should have about 1¼ cups of mashed sweet potato. Mix in the buttermilk, then set aside.
Meanwhile, in a medium bowl stir together both flours, the baking powder, baking soda, salt, nutmeg and allspice.
In another medium bowl, combine the butter and both sugars. Use an electric mixer to beat until the mixture is light and fluffy, about 3 minutes. Using a spatula, scrape down the sides of the bowl. Add the egg and vanilla, then mix on medium speed for about 1 minute, until thoroughly combined. Scrape down the sides of the bowl.
Add half the flour mixture and beat the batter on low speed just until the mixture is partly mixed. Add half the buttermilk-sweet potato mixture and mix until combined. Add the remaining dry ingredients and mix until just combined, then mix in the remaining buttermilk mixture.
Divide the batter among the prepared muffin cups. Top it with the crystallized ginger and bake on the middle rack of the oven for 25-30 minutes, or until the tops are golden and a toothpick inserted at the center comes out clean. Remove the muffins from the pan and tip on their sides on a cooling rack; this prevents the bottoms from getting soggy. Let cool 10 minutes before serving. They are best eaten while still hot.
Cook's note: White whole-wheat flour is available in the baking aisle of most grocers. It has all the nutrition of regular whole-wheat flour, but it is made from a different variety of wheat that produces a flour with a lighter taste, texture and color.
Nutrition values per serving: 180 calories, 5 g fat (3 g saturated), 29 g carbohydrates, 2 g fiber, 4 g protein, 30 mg cholesterol, 240 mg sodium.
Sara Moulton for The Associated Press