Healthy, quick, and flavorful, this zucchini and squash casserole is the best healthy dish for summer! Yellow squash and zucchini are baked in the oven to perfection with a crispy crust made from Parmesan cheese and breadcrumbs. This simple casserole is amazing for summer picnics and potlucks, and makes the perfect side dish for any meal! Try this easy recipe now!