Step 1: Preheat your oven to 400-425°F (200-220°C) and line two large baking sheets with parchment paper.
Step 2: Peel the sweet potatoes and cut them into uniform sticks, about 1/4 to 1/3 inch thick and 3-4 inches long. Aim for consistency to ensure even cooking.
Step 3: Place the cut sweet potatoes in a large bowl and cover them completely with cold water. Let them soak for at least 30 minutes, or up to an hour, to draw out excess starch.
Step 4: Drain the sweet potatoes thoroughly. Using a salad spinner and/or clean kitchen towels, pat them completely dry. This step is crucial for crispiness.
Step 5: In the large bowl, drizzle the dried sweet potato fries with olive oil and toss to coat evenly.
Step 6: Sprinkle the cornstarch over the oiled fries, followed by salt, black pepper, smoked paprika, and garlic powder. Toss again until all fries are evenly coated with the starch and seasonings.
Step 7: Arrange the seasoned sweet potato fries in a single layer on the prepared baking sheets, ensuring there is plenty of space between each fry. Do not overcrowd the pans, as this will lead to steaming instead of roasting.
Step 8: Bake for 15-20 minutes. Carefully remove the baking sheets from the oven and, using a spatula, flip each fry to ensure even browning. Return to the oven.
Step 9: Continue baking for another 10-15 minutes, or until the fries are golden brown and perfectly crispy. Keep a close eye on them during the final minutes to prevent burning.
Step 10: Serve immediately with your favorite dipping sauces and enjoy your perfectly crispy baked sweet potato fries!