Typically I don't do much more to zucchini than a quick boil, drain and finish with butter/oil and/or garlic and other herbs so the prepping the day before isn't so much of an issue. My father loved the fried rounds, but who has time to fuss with that on top of the stove with all the other stuff going on.
Well, you could prepare the crumbs and cut up the zucchini the day before (I'd cut it into smaller pieces than spears so maybe make a bit more coating mixture), then it's a simple shake and bake:
https://www.cooks.com/recipe/3f9hx79...-zucchini.html
My son and daughter in law are vegan, I make sort of a vegan version of this:
https://www.cooks.com/recipe/593sy9a...-parmesan.html
That definitely can be made the day before, and even cooked, I think it's one of those things that are even better reheated.
Lots of variations on this casserole,
https://www.cooks.com/recipe/m96dl8t...casserole.html