To cook the sweet potatoes, bring a large pot of water to a boil. Peel and cube the potatoes into 1-1/2-inch pieces then boil for about 20-30 minutes or until tender. Drain thoroughly then mash with a fork or potato masher in a large bowl.
Preheat oven to 425º F.
Stir in the butter and milk into the potatoes. Add 1-3/4 cups of the flour, baking powder, sugar and salt and mix until combined. Add the rest of the 1/4 cup of flour and combine.
Turn dough out on a floured surface and knead 5-6 times. Roll dough flat to half-inch thickness.
Use a 2-inch biscuit cutter to cut out the biscuits from the dough or use a sharp knife to cut biscuits into 2-inch square pieces.
Spray a baking sheet with nonfat cooking spray then place biscuit pieces close together on the sheet.
Brush the top of each biscuit with nonfat milk then lightly sprinkle with cinnamon or nutmeg.
Bake biscuits for about 15 minutes or until golden.
TEXT VERSION OF NUTRITION FACTS: Serving Size: 1 biscuit (36 g) Servings Per Recipe: 18