Measure out 2.5 cups of pre-soaked chickpeas.
Roughly chop the spring onion, garlic, coriander , mint and put these in a food processor. Add a handful of the chickpeas and pulse until you get a coarse mixture.
Add the spices, salt, pepper and and harissa/chipotle, pulse again, then gradually add the remaining chickpeas.
Pulse until you get a coarse but sticky texture, resembling fine couscous, scraping the mixture down the sides of the food processor. (You might need to divide the mixture into two batches, depending on the size of your food processor.)
When you’re happy with the consistency (it should be sticky) transfer the mixture to a bowl.
Add the lemon zest and baking powder. Combine well and cover. Chill for a couple of hours.
When you’re ready to cook the falafels take the mixture out of the fridge.
Make small balls or patties using your hands. If the mixture is not binding well, add some chickpea flour to it.
Place the falafels onto a plate.
Pour some oil in a small saucepan to a depth of 2-3cm. Heat the oil over medium heat. When it’s hot, place 5-6 falafels in the oil and fry for 2-3 minutes on each side until golden brown all over.
Using a slotted spoon, transfer them to a plate, lined with kitchen paper towels.
Fry the remaining falafels. (You should get about 18 falafels).
Serve at room temperature.