Step 1: Preheat and Prepare
Preheat your oven to 425°F (220°C). Line a large baking sheet with parchment paper for easy cleanup. For even better browning on the bottom, you can bake directly on an unlined metal pan lightly greased with oil.

Step 2: Cut the Wedges
Scrub the sweet potatoes thoroughly under running water and pat them dry. Trim off the ends. Cut each potato in half lengthwise. Place each half cut-side down and cut it in half lengthwise again, so you have four long quarters. Depending on the thickness of the potato, you can cut each quarter in half again to create 8 uniform wedges per potato. The goal is to have wedges that are about ½ to ¾-inch thick.

Step 3: The Optional (but Recommended) Soak
Place the cut wedges in a large bowl and cover them with cold water. Let them soak for at least 30 minutes and up to a few hours. This step helps to draw out excess starch, which allows the wedges to become crispier.

Step 4: Dry the Wedges THOROUGHLY
This is the most critical step. Drain the soaked potatoes (or rinse the un-soaked ones). Spread them out on a clean kitchen towel or several layers of paper towels. Pat them completely dry. Moisture is the enemy of crispiness, so be meticulous here.

Step 5: Season the Wedges
In a small bowl, whisk together the cornstarch, smoked paprika, garlic powder, onion powder, salt, and pepper. In a large, dry bowl, place your thoroughly dried wedges. Drizzle them with the 2 tablespoons of oil and toss well until every wedge has a thin, even sheen of oil. Now, sprinkle the cornstarch and spice mixture over the oiled wedges. Toss again until every wedge is evenly coated in the seasoning.

Step 6: Arrange on the Baking Sheet
Arrange the seasoned wedges on the prepared baking sheet in a single layer. It is crucial that you do not crowd the pan. Make sure there is space between each wedge. If the wedges are too close together, they will steam instead of roast, resulting in soggy wedges. Use two baking sheets if necessary.

Step 7: Bake to Perfection
Place the baking sheet in the preheated oven and bake for 15-20 minutes. Remove the pan from the oven and carefully flip each wedge over using tongs or a spatula. Return the pan to the oven and bake for another 10-15 minutes, or until the wedges are golden brown, crispy on the outside, and tender on the inside.

Step 8: Serve Immediately
For the best and crispiest texture, serve the sweet potato wedges immediately while they are hot.