Put the dry chickpeas in a large bowl, cover with enough water (the chickpeas will double in size!) and let them sit covered overnight.
Peel the onions and garlic cloves. Put them in a food processor and chop. In a pan with a teaspoon of canola oil, add the chopped onions, garlic, and cumin and let it cook on medium-high heat for about 5 minutes or until they start to brown.
Drain and rinse the chickpeas and then work in batches by adding the first batch into the food processor and chop until the pieces are really small (you don't want to make hummus). In one batch add in the parsley to chop it as well. Repeat until you've used up all the chickpeas. Transfer everything to a huge bowl.
Add the lemon juice, cayenne pepper, salt, ground pepper, baking powder, and the onions and garlic. Mix well.
Preheat the oven to 400°F/200°C.
Add in the chickpea flour and olive oil. Mix the chickpea mixture well and form little balls. If the dough does not stick together enough, add more chickpea flour and oil.
Put the falafel on a baking tray and bake them in the oven for about 25 minutes or until they turn golden.
You can eat the falafel like that or put them in a pan with a little oil for reheating when you need them. They freeze very well, so you will have a nice stash of homemade falafel in your freezer, which is super convenient!