Cut the potatoes lengthwise into 1/4 inch thin slices; then cut each slice into 1/4- inch fries. (A mandolin is also helpful here).
Spray the potatoes generously with oil.
In batches, place the potatoes in the basket in an even layer without overlapping or crowding, air fry 380F about 7-8 minutes on each side, until golden and crisp.
Meanwhile, in a large bowl combine chili powder, garlic powder, paprika and salt; mix in Parmesan cheese and mix well.
When the fries are done, add to the bowl and toss to coat.
Return back to the air fryer and cook 1 minute more.