Combine first 5 ingredients in a medium bowl, stirring with a whisk. Coat both sides of zucchini slices with cooking spray. Dredge zucchini slices in breadcrumb mixture, pressing gently to coat. Place coated slices on a foil-lined baking sheet coated with cooking spray.
Bake at 425° for 30 minutes or until browned and crisp, turning after 15 minutes. Serve immediately.