Preheat the oven to 400°F and line a large baking sheet with parchment paper. In a large food processor, place the chickpeas (note: the chickpeas will have expanded during the soak time, be sure to use ALL of them here), shallot, garlic, lemon zest, cumin, coriander, salt, cayenne, baking powder, cilantro, parsley, and olive oil. Pulse until well combined but not pureed. Use a spatula to scrape down the sides of the bowl as needed. Use a 2-tablespoon scoop and your hands to form the mixture into 12 to 15 thick patties (be careful not to pack them too tight or your falafel will be dense). If they're not holding together, give the mixture a few more pulses in the food processor. Place the patties on the baking sheet. Drizzle generously with olive oil (this is the key to making these moist and crisp since we're not frying) and bake for 14 minutes. Flip and bake for 10 to 12 minutes more or until golden brown and crisp on the outside. During the last few minutes of baking, wrap the pita in foil and warm in the oven. Assemble pitas with a slather of hummus, diced veggies, falafel, herbs, pickled red onions, and generous drizzles of tahini sauce.