Place a rack in center of the oven and preheat to 435 degrees. Grease a baking sheet with butter, oil or cooking spray.
2
In a small bowl, whisk together the sweet potato and 1/3 cup of milk. set aside.
3
in a large bowl, whisk together the flour, sugar, baking powder and salt. Cut in the butter (cold, unsalted, small cubes) with your hands, a pastry blender or two knives until the mixture resembles course meal. Add the sweet potato mixture and fold gently to combine. Add the remaining milk a little at a time until all the flour is moistened. the amount of milk needed will depend on the moisture of the sweet potato.
4
Sprinkle a small handful of flour on a work surface. turn the dough out and knead lightly 2 to 3 times with the palm of your hand until the mixture comes together. Pat the dough out into a 1/2 inch thick round.
5
Using a 2 1/2 inch round biscuit cutter, cut the dough into biscuits. Gently re-roll the scraps and cut out more biscuits. Place the biscuits on the prepared baking sheet and bake until light golden brown and firm to the touch, 12 to 14 minutes. serve warm.
