1In a medium bowl combine flour, sugar, baking powder, baking soda, cinnamon, and salt. Set aside
2In a large bowl combine eggs, sour cream and sweet potato. Gradually add flour mixture.
Turn dough out onto a heavely floured surface. Knead in flour with hands as needed (dough will be sticky).
Roll out dough to 1/2 inch thickness. Cut out dough with a 2 1/4 inch round cutter. Cut out center of doughnuts with a 3/4 inch cutter if your cutter doesn't already have a hole cutter in it.
3In a dutch oven, heat vegetable oil to 360 degrees. Cook doughnuts, in batches, in hot oil, 1 to 2 minutes per side. or until lightly browned. drain on paper towels, Ice top with icing sprinkle with chopped pecans
4For Icing combine ingredents and stir well. add additional milk to desired consistency.