For an extra layer of flavor, try adding a pinch of garlic powder to the zucchini while sautéing. Feel free to substitute other cheeses, such as Gruyere or Monterey Jack, for a different flavor profile. If you don't have panko bread crumbs, regular bread crumbs can be used, but the texture will be slightly different. The casserole can be prepared ahead of time and refrigerated until ready to bake. Add about 10-15 minutes to the baking time if baking from cold.