1. In a large mixing bowl, combine the mashed chickpeas, grated zucchini, red onion, breadcrumbs, egg, cumin, smoked paprika, coriander, garlic powder, salt, and black pepper. Use a silicone spatula to mix until well combined.
2. Divide the mixture into 4 equal portions and shape into patties using your hands or an offset spatula.
3. Heat a cast iron skillet over medium heat and add the olive oil. Once hot, place the patties in the skillet and use a spatula to smash them down slightly.
4. Cook for 4-5 minutes on each side, or until golden brown and crispy. Use a digital kitchen scale to ensure even patty sizes if needed.
5. Toast the burger buns lightly in the skillet or on a baking sheet in the oven for 2 minutes.
6. Assemble the burgers by placing a patty on each bun, then topping with lettuce, tomato, and a drizzle of tahini sauce.
7. Serve immediately with a side of your choice.