Preheat oven to 425°.
Combine first 5 ingredients in a medium bowl, stirring with a whisk. Place milk in a shallow bowl. Dip zucchini slices in milk, and dredge in breadcrumb mixture. Place coated slices on an ovenproof wire rack coated with cooking spray; place rack on a baking sheet. Bake at 425° for 30 minutes or until browned and crisp. Serve immediately.