Preheat the oven to 425°F (220°C). Line a large rimmed baking sheet with parchment/foil, or lightly grease it.
Scrub the potatoes, rinse, and pat very dry. Slice each potato in half lengthwise. Place cut-side down and cut each half into 3–4 wedges (aim for about 1-inch thickness at the widest part).
Add potato wedges to a large bowl. Drizzle with olive oil and toss to coat. If using cornstarch for extra crispiness, sprinkle it over the wedges now and toss again until no dry powder remains.
Add garlic powder, onion powder, paprika, salt, black pepper, and (optional) cayenne and/or chili powder. Toss thoroughly so the wedges are evenly seasoned. If using Parmesan, toss it in last.
Arrange wedges on the baking sheet in a single layer, skin-side down where possible, leaving space between pieces (don’t crowd the pan).
Bake for 30–35 minutes, flipping once halfway through, until golden brown and crisp outside and tender in the center (a fork should slide in easily).
Serve immediately with your favorite dips (ketchup, ranch, sour cream, BBQ sauce, or garlic aioli). For leftovers, reheat at 400°F for about 10 minutes to re-crisp.