Preheat oven to 400°F.
Mix the flour, brown sugar, baking powder, cinnamon, nutmeg, and salt together.
2 cups all-purpose flour, ¼ cup brown sugar, 2 teaspoons baking powder, ½ teaspoon ground cinnamon, ¼ teaspoon ground nutmeg, ½ teaspoon kosher salt
Use the large holes on a cheese grater to grate the butter and work it into the dry mix with your hands.
6 tablespoons unsalted butter
Whisk together the milk and sweet potato and add to the flour mixture. Stir to combine.
⅔ cup whole milk, ¾ cup mashed sweet potato
Turn the dough out onto a floured surface. Then, fold it in half 3-4 times, pressing down to flatten after each time.
Using a rolling pin, roll out the dough to 1- to 2-inch thickness.
Use a round cookie cutter or the opening of a glass to cut out 10 rounds.
Bake for 17-18 minutes, or until the biscuits are golden brown.