Heat oven to 425 degrees. In a pie plate, combine cornmeal, parmesan cheese and flour. Place buttermilk in a med. Bowl. Dip squash in buttermilk; allow excess to drip off. Dredge in cornmeal mixture: turn to coat well. Place on a greased baking sheet. Coat squash well with olive oil cooking spray. Bake 20 mins, turning once, or until golden brown. If you have leftovers don't reheat in a microwave or they will get soggy. Instead bake a 350 degrees for 10 mins. Or until heated through and crisp.
