Combine, breadcrumbs, parmesan cheese, black pepper, salt, garlic powder and cayenne pepper in a small mixing bowl. Dip zucchini slices into milk and dredge into bread crumbs to coat both sides. Note: It may be necessary to press crumbs onto zucchini slices to ensure the crumbs stick.
Arrange zucchini slices on a non-stick cookie sheet and lightly mist with a non-stick cooking spray. (If using a rack, place rack on a cookie sheet)
Bake 15 minutes, turn over and continue baking until golden for an additional 10-15 minutes (being careful not to burn). Allow to cool to room temperature before storing in an airtight container.