Preheat oven to 400 degrees. Line 2 baking sheets with foil and spray lightly with vegetable spray.
Slice zuchinni or squash into 1/4 inch thick rounds. Toss rounds with oil, coating well.
In a wide bowl or plate combine breadcrumbs, parmesan, salt and pepper. Place rounds in parmesan breadcrumb mixture, coating both sides of each round, pressing to adhere. The mixture will not completely cover each round but provides a light coating on each side.
Place rounds in a single layer on both baking sheets. Sprinkle any remaining breadcrumb mixture over the rounds.
Bake for about 22 to 27 minutes, until golden brown. There is no need to flip them during baking. they crisp on both sides on their own.
Optional: about the last 5 minutes of cooking add a few bacon bits on top and sprinkle with cheese if desired.