Place 8 ounces dried chickpeas and 1/4 teaspoon baking soda in a large bowl and cover with a few inches of cold water. Let sit at cool room temperature at least 18 and up to 24 hours. Drain, rinse with fresh water, and drain well again.
Coarsely chop 1 small shallot and 2 garlic cloves and add to the bowl of a food processor fit with a blade attachment. Add the chickpeas, 1 cup fresh parsley leaves and tender stems, 1 cup fresh cilantro leaves and tender stems, 3 tablespoons olive oil, 2 teaspoons kosher salt, 1 1/2 teaspoons ground cumin, 1/2 teaspoon baking powder, and 1/8 teaspoon cayenne pepper. Pulse for 10 seconds, then scrape down the sides with a rubber spatula.
Repeat pulsing and scraping 2 to 3 more times ,until the mixture comes together and the chickpeas are broken down but haven't lost all of their texture. If the mixture isn’t coming together, gradually pulse in all-purpose or chickpea flour 1 tablespoon at a time. Transfer the mixture to a bowl and refrigerate for at least 30 minutes.
Heat the air fryer to 350°F.
Lightly coat an air fryer basket with cooking spray. Using a tablespoon or a small cookie scoop, scoop the mixture into damp hands and roll into balls. Cook in 2 batches: place the falafel in the basket in a single layer. Air fry for 10 minutes. Flip and air fry until golden-brown, about 5 minutes more.
Serve the falafel with a dipping sauce or build a sandwich in a warmed pita. The falafel are best eaten immediately.