1. Preheat the oven to 425 degrees.
2. Wash and dry the potatoes and, with the skin on, slice into 1/2-inch-thick rounds; cut the rounds into 1/2-inch-thick finger-shaped pieces. Toss the potatoes in a bowl with the oil, chili powder, garlic powder and salt.
3. On a baking sheet, spread the sweet potato fries in a single layer and roast, stirring every 10 minutes, until brown and tender, 30 to 35 minutes. Remove from the oven, transfer to a platter or bowl and sprinkle with a little more salt.
Calories per serving, sweet potato fries: 89