Pulse onion, garlic, parsley, and cilantro in a food processor until coarsely chopped.
Pulse in coriander, cumin, and lemon juice, and season with salt & pepper to taste.
Add the garbanzo beans and pulse until a thick paste that can be rolled into balls forms.
Add 1-2 tablespoons of flour to thicken if the paste is too watery. Add the flour 1 tablespoon at a time, pulsing to combine until it reaches the right consistency.
Scoop and roll into 1½ tablespoon-sized balls.
Spray the air fryer basket with olive oil. Add the falafels in a single layer. Do not overcrowd. Spray spray each falafel with olive oil.
Air fry the falafel for 13-16 minutes, until golden brown and crispy.
Notes
If making ahead, use within a day because of the raw garlic. Leftover cooked falafel will keep in the refrigerator in an airtight container for up to three days.