Drain soaked chickpeas well and pat dry. Add to a food processor with onion, garlic, parsley, coriander, cumin, coriander powder, cardamom, baking soda, and salt. Pulse until the mixture resembles coarse, slightly grainy breadcrumbs- do not over-blend into a paste.
Refrigerate the mixture uncovered for at least 30 minutes.
Scoop and shape the mixture into 16 balls or patties, about 1 1/4 ounces each. Press firmly so they hold together.
Preheat air fryer to 375°F for 3 minutes. Lightly brush or spray the basket with oil.
Brush the falafel generously with olive oil. Place in a single layer in the basket. Air fry for 10 minutes, flip carefully, spray again, then cook a further 6 minutes, or until golden and crisp all over.
Serve immediately.
Notes
To store: Leftover falafel will keep well in the fridge, covered, for up to three days. To freeze: Place the cooled falafel in a Ziploc bag and freeze for up to 2 months. Thaw overnight in the fridge. Reheating: I like to reheat leftovers back in the air fryer at 400°F. If you can, add a tiny bit more oil on the outsides for maximum crispiness.