Preheat oven to 375 degrees F.
Pierce sweet potato in several places. Bake potato until very tender, approximately 1 hour. Remove from oven. Cut potato in half and cool slightly. Scoop flesh from potato into small bowl and cool completely.
Place 1 cup baked and cooled sweet potato flesh into a large bowl. Add butter and brown sugar; beat until smooth; set aside.
Sift flour, baking powder, salt,baking soda, and cinnamon into a medium bowl. Mix dry ingredients into sweet potato mixture, alternately with buttermilk in three (3) additions, beginning and ending with dry ingredients.
Transfer dough to a generously floured surface. Roll to 3/4-inch thickness. Using a 2 1/4-inch round cookie cutter, cut out biscuits; place on an ungreased baking sheet. Gather scraps into ball; reroll and cut.
NOTE: If you need to hold the uncooked biscuits, the cut dough rounds can be refrigerated for up to 1 hour.
Bake biscuits until golden and puffed, approximately 20 to 25 minutes. Remove from oven and transfer from baking sheet to cooling rack and cool slightly.
Serve biscuits warm or at room temperature.
Makes 10 to 12 biscuits.
Sweet Potato Biscuits Recipe: https://whatscookingamerica.net/bread/sweetpotato.htm