Prep the zucchini: Grate zucchini and sprinkle with 1/2 tsp salt. Let sit in a bowl for 10–15 minutes. Then, using a clean kitchen towel or cheesecloth, squeeze out as much moisture as possible.
Make the flax egg: In a small bowl, mix ground flaxseed with 3 tbsp water. Let sit for 5–10 minutes until it gels.
Mash chickpeas: In a large mixing bowl, mash the chickpeas with a fork or potato masher, leaving a few chunks for texture.
Mix everything: Add the squeezed zucchini, flax egg, oat flour, lemon juice, garlic, onion, parsley, cumin, paprika, and optional nutritional yeast to the mashed chickpeas. Stir until well combined. Season with salt and pepper to taste.
Let the mixture rest: Cover the bowl and let the mixture sit for 10–15 minutes. This allows the flour and flax to absorb moisture and makes the mixture easier to shape.
Form patties: With damp hands, shape the mixture into small patties (about 10-12). If the mixture still feels too wet, add a bit more flour, 1 tablespoon at a time.
Bake: Place the patties on a parchment-lined baking sheet. Bake at 400°F for 20 minutes, then flip and bake for another 15–20 minutes until golden brown and firm.
Cool and serve: Let the fritters cool slightly before serving. They firm up even more as they cool.