Place the parsley, coriander and garlic in the bowl of a food processor and pulse three to four times.
Add the drained chickpeas, cracked wheat or quinoa, ground coriander, ground cumin, cayenne, salt, ground black pepper, baking powder and turmeric and process until the mixture has the texture of cornmeal. When you press it into a ball using your fingers, it should hold.
Remove the mixture to a bowl and mix in the onion and breadcrumbs.
Heat a quarter of an inch layer of oil in a skillet. The oil should be around 350 degrees Fahrenheit. If you don't have an oil thermometer, heat the oil to a point where a piece of the falafel batter dropped into it immediately bubbles and rises, but doesn't brown immediately.
Shape the mixture into patties about 3 inches in diameter and about a quarter of an inch thick. If you want the patties to be crunchy, shape them as thinly as you can. Thicker patties are fine, however, but don't make them too thick as you want the chickpeas to cook through on the inside.
Place the patties in the hot oil at least an inch apart. Do not overcrowd the pan because when you do that the oil temperature drops and the patties won't cook properly. Also, when you overcrowd the pan the patties will steam rather than fry, which means they won't be as crunchy.
Fry the burger patties on both sides until golden-brown. Remove to a paper-lined plate.