Place an oven rack in the upper-middle position and preheat the oven to 400 F. Grease a lightly-colored, non-stick baking sheet with olive oil spray.
Set aside. Combine cornstarch, salt, pepper, paprika, and garlic powder in a small bowl and set aside.
Place sliced sweet potatoes in a large mixing bowl. Add sliced sweet potato fries to a large bowl. Toss with olive oil and the cornstarch mixture. Mix until all fries are evenly coated.
Spread fries out evenly, leaving space between each piece.
Place the baking tray into the preheated oven for 15 minutes.
Remove from the over, flip fries over gently, and bake for another 15 minutes, until the edges are crispy and the fries are tender. Serve immediately with ketchup or other condiments.