Set air fryer to 400° Fahrenheit and allow air fryer to preheat. While air fryer preheats, peel 1 large sweet potato.
Place peeled sweet potato on cutting board. Cut potato in half across center, then cut each sweet potato half in half vertically. Continue cutting each quarter until entire potato has been cut into equally-thick sticks.
Place all potato sticks in medium bowl. Pour ½ teaspoon neutral-flavored oil over potato sticks, then toss potatoes with tongs to coat each stick in oil on all sides. Add another ½ teaspoon oil as needed depending on number and size of potato sticks. Set bowl aside when finished.
Add ½ teaspoon garlic powder, ¼ teaspoon paprika, 1 teaspoon salt, 1 pinch cinnamon, and plenty of freshly cracked black pepper to small mixing bowl. Stir spices together until well blended.
Sprinkle spice blend over sweet potato sticks. Toss potato sticks with tongs until well coated in spices.
Transfer sweet potato sticks to air fryer basket, working in batches as needed to avoid overcrowding, and arrange potatoes in single, flat layer.
Return basket to air fryer. Air fry sweet potatoes 4 minutes, then pause air fryer. Remove basket from air fryer and shake basket to toss fries.
Return basket to air fryer. Air fry sweet potatoes 3 minutes more, then check doneness. Return basket to air fryer if needed and continue frying sweet potatoes, checking every 1 minute, until fries look matte and are lightly browned on ends and edges.
When fries are cooked as desired, carefully transfer fries to large bowl or plate. Repeat process as needed until all sweet potato fries have been air fried.
Serve sweet potato fries warm with dipping sauce of choice (optional).