– Zucchini. It's best to use small to medium sized zucchini. Yellow squash works as well. – Panko breadcrumbs. Panko is a must here. Regular breadcrumbs don't crisp quite as nicely. Batter: – Flour. All-purpose flour. – Oat Milk. Or other non-dairy milk. – Paprika. – Onion powder. – Salt & Pepper.