This recipe is from Martha's friend Salli LaGrone; she serves it with a simple but flavorful country ham.
Source: Martha Stewart Living, June 2001
Yield Makes 3 dozen 2-inch or 5 dozen 1 1/2-inch biscuits
6 tablespoons chilled unsalted butter, cut into small pieces, plus 2 tablespoons, melted
One 1-by-2-inch strip orange rind
2 cups unbleached all-purpose flour, plus more for patting out
1 tablespoon baking powder
1/2 teaspoon baking soda
3/4 teaspoon salt
3 tablespoons light-brown sugar
Generous pinch ground ginger
1 tablespoon freshly grated orange zest
1 cup well-cooked and mashed sweet potato (1 medium)
2/3 cup buttermilk
Preheat oven to 400 degrees. Line a baking sheet with a Silpat. In a small bowl, combine melted butter and strip of orange rind; set aside.
In a medium bowl, combine flour, baking powder, baking soda, salt, brown sugar, ginger, and grated zest. Using a pastry cutter or two knives, cut chilled butter into the flour mixture until it resembles coarse meal.
Make a well in the center, and add sweet potato. Using a fork, stir in the sweet potato. Add buttermilk, and stir just until the dough comes together. Do not overmix.
Lightly dust dough with flour. Turn dough onto a lightly floured surface, and knead gently six to eight times.
On a clean work surface, pat out the dough to a 1/2-inch thickness. Using a floured 1 1/2-inch or 2-inch biscuit cutter, cut out the biscuits as close together as possible. Transfer to prepared baking sheet. The scraps may be patted out again once more. Prick the tops of each biscuit a few times. Brush the tops with the reserved orange-flavored butter. Bake until golden brown, 15 to 18 minutes for the small biscuits and 20 to 25 minutes for the large biscuits.