Updated: December 15, 2012 6:01AM
MAKES 12 SERVINGS
Start to finish: 1 hour (30 minutes active)
3/4 to 1 pound sweet potatoes (2 small or 1 medium)1
1/2 cups buttermilk 1 cup white whole wheat flour 1 cup all-purpose flour 1 teaspoon baking powder
1 cup white whole wheat flour
1 cup all-purpose flour
1 teaspoon baking powder
1/2 teaspoon table salt
1/2 teaspoon nutmeg, preferably freshly ground
1/4 teaspoon ground allspice
1/4 cup ( 1/2 stick) butter, room
1/4 cup packed dark brown sugar 1 large egg 2 teaspoons vanilla extract
1 large egg
2 teaspoons vanilla extract
Heat 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 until tender, about 10 minutes. Let cool, then peel and, in a medium bowl, mash with a fork. You should have about 11/4 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 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 to 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.