Cover chickpeas in water in a large pot and soak overnight at room temperature.
Finely chop the white onion; chop green onions, parsley and garlic.
Drain and rinse the chickpeas. Place in a food processor along with the green onion, white onion, parsley, garlic, lemon juice, flour, salt, coriander, cumin, black pepper and cayenne pepper.
Pulse until mixture reaches a course meal to paste texture. (Do not over process). You may have to do this in 2 batches depending on size of your food processor. Once done, blend together with a fork and remove any large pieces of chickpeas.
Refrigerate the falafel mixture for 2 hours.
Preheat oven to 400° F.
Spray a muffin tin with cooking spray.
Use a scoop or roll mixture into 24 balls; add directly into muffin tin. Place in the oven and bake for 7 minutes. Remove, turn falafel over, and then bake 7 minutes longer.