Preheat oven to 400°F.
Place flour, sugar, baking powder, salt, cinnamon, and pepper into a bowl and whisk together.
Cut in butter with a pastry knife or using your fingers until a fine grainy texture forms.
Fold in rosemary, sweet potato and buttermilk and stir until dough just comes together.
Turn dough onto a clean surface and cut out 3 inch rounds using a circle cutter. Place biscuits onto a baking sheet lined with parchment, about 1 inch apart, and bake for 15 to 20 minutes or until the tops are golden brown and the biscuits have baked through. Serve warm.
To store: Place biscuits in an airtight container and place in the refrigerator for up to 3 days. Warm before serving.