Preheat oven to 450.
Mix flour, baking powder, tumeric, cinnamon, salt and sugar together.
Add cold butter and cut in with your hands or pastry cutter. A good tip is to freeze the butter for 15 minutes, to keep everything cold.
Add in cold sweet potato with your hands until fully incorporated.
Add in buttermilk and mix thoroughly.
Knead 6-8 times with hands. Pat into a dough about 1 inch thick and cut biscuits.
Place in cast iron pan touching and bake for 15 minutes or until golden. Brush with milk, cream, or melted butter.
Makes 10-12 biscuits.