Preheat the oven to 425°F. Line a baking sheet with parchment paper.
Peel the sweet potatoes and cut them into sticks about 1/4 inch wide and 3 inches long.
Soak the sweet potatoes in cold water for 35 minutes. Drain water and pat dry with paper towels.
Put the fries in a large resealable bag with the cornstarch and shake to coat the fries. Discard excess cornstarch.
In a large bowl, toss the sweet potato sticks with olive oil, salt, pepper, garlic powder, onion powder, and paprika until evenly coated.
Spread the sweet potatoes in a single layer on the prepared baking sheet.
Bake in the preheated oven for 15 minutes, then flip the fries and bake for another 15 minutes or until they are golden and crispy.
Serve with ketchup or preferred dipping sauce.