Preheat the air fryer to 380°F and spray the inside of your air fryer basket with nonstick cooking spray. (I use the Cosori 5.8 quart XL and love it)
Scrub the sweet potatoes under cold running water and dry them completely. Peel or leave the skin on (I like to leave it on).
Cut the potatoes in half lengthwise. Place the two halves cut-side down onto the cutting board and cut each half lengthwise into ¼-inch thick strips. Turn the strips on their side and slice each into ¼-inch sticks. If your fries are longer than 6 inches or so, cut them in half crosswise. Transfer to a large mixing bowl.
Place the fries in a large mixing bowl and toss with extra virgin olive oil, sugar (optional), salt, garlic powder, paprika, cinnamon (if desired), and black pepper.
Working in batches, transfer just enough sweet potato fries to your air fryer basket so that they are in a single layer.
Cook for 5 minutes, slide the basket out and flip the fries/shake the basket, then continue cooking for an additional 5 minutes. Check again after 5 minutes. If your fries need more time, carefully shake the basket before cooking for an additional 3-5 minutes (cooking time will vary by air fryer model and thickness of your sweet potato fries).
Remove the crispy sweet potato fries to a clean plate and sprinkle with additional salt, as needed. Repeat with the remaining sweet potatoes until they have all been cooked.
Serve with ketchup and/or your favorite dipping sauce. Enjoy!