Preheat oven to 425°F (220°C) and line a rimmed baking sheet with parchment paper. (assumption)
Peel or scrub the sweet potatoes and cut into even sticks (about 1/4–1/2 inch thick / 6–12 mm).
Pat fries very dry with paper towels.
Toss fries with cornstarch, garlic powder, black pepper, paprika, and a pinch of kosher salt.
Drizzle grapeseed oil over fries and toss until evenly coated.
Spread fries in a single layer on the baking sheet with space between pieces.
Bake 25–30 minutes, flipping halfway, until browned and tender. (assumption)
Taste and season with more kosher salt if needed. Serve hot.