Servings: Makes 15–18 biscuits
Preheat oven to 400°.
Combine flour, baking powder, brown sugar, cinnamon, allspice and salt in a bowl. Add cold butter and vegetable shortening and mix until crumbly. Add mashed sweet potatoes and milk. Stir until you have dough. Chill dough in refrigerator for 10 to 15 minutes. Knead dough on floured surface—do not overwork. Roll dough to a 1/2-inch thickness and cut with a 1.5-inch biscuit cutter. Place biscuits on a baking sheet lined with parchment paper. Brush tops of biscuits with melted butter. Bake for 12 minutes or until nicely browned.