Combine the sugar and cinnamon in a small bowl and mix well. Set aside.
Heat the vegetable oil in a very large, deep pot or heat an electric fryer to 360ºF. Fry the sweet potatoes, in batches, until golden brown, about 8 minutes. Drain on paper towels.
Sprinkle with the cinnamon sugar and serve hot.
Yield: about 20 servings