1. Cut potatoes in half lengthwise, then cut each half in thirds lengthwise. You'll have 6 wedges from each potato.
2. Place the potatoes in a large bowl with cold water and soak for 20 min to remove some of starch that causes the potatoes to stick. Drain them with paper towels.
3. In a separate bowl, mix together oil, paprika, garlic powder, chili powder and salt.
4. In batches, add the potato wedges to the bowl to coat them lightly. Make sure they are covered with oil.
5. Preheat oven to 425 degrees F (220 degrees C).
6. Place the potato wedges in a single layer on a large baking sheet, previously covered with foil. Bake for 30 to 35 minutes, until lightly brown, crispy outside and tender inside.
7. Remove from the oven. Drain on paper towels. Sprinkle with Parmesan cheese and parsley. Serve with ketchup.