Preheat your oven to 400°F (200°C). Line two large baking sheets with parchment paper to prevent sticking and ensure easier cleanup.

Peel the sweet potatoes. Cut each sweet potato lengthwise into 1/4-inch thick planks, then cut the planks into 1/4-inch thick fries. Aim for uniform size for even cooking.

Place the cut sweet potato fries in a large mixing bowl. Add the olive oil, sea salt, black pepper, paprika, and garlic powder (if using). If you're using cornstarch for extra crispiness, sprinkle it over the fries now.

Toss everything together thoroughly, ensuring all the fries are evenly coated with oil and seasonings. It's important that each fry gets a good coating.

Arrange the seasoned sweet potato fries in a single layer on the prepared baking sheets. Make sure they are not overlapping, as this will steam them instead of crisping them. If necessary, use a third baking sheet.

Bake for 15 minutes, then flip the fries over using a spatula. Return to the oven and continue baking for another 10-15 minutes, or until the fries are golden brown and crispy to your liking. Keep an eye on them during the last few minutes to prevent burning, as oven temperatures can vary.

Remove from the oven and serve immediately. They are best enjoyed hot and fresh, perhaps with a side of ketchup, aioli, or your favorite dipping sauce.