Preheat broiler. Lightly coat zucchini and garlic with cooking spray; place on a baking sheet coated with cooking spray. Broil 5 minutes or until garlic and zucchini are lightly browned. Remove garlic from baking sheet; mince. Set zucchini aside. Combine the garlic, breadcrumbs, and parmesan cheese; set aside. Combine milk and next 5 ingredients (milk through egg) in a medium bowl, stirring with a whisk. Combine tomatoes, basil and oil in a bowl; set aside.
Preheat oven to 400º.
Spread 1/2 cup milk misture in bottom of an 11x7-inch baking dish coated with cooking spray. Arrance zucchini slices over milk mixture to cover the bottom of the dish, and top with 1/3 cup breadcrumb mixture and 1/2 cup milk mixture. Repeat layers, ending with the zucchini. Top with the tomato mixture, and sprinkle with the remaining breadcrumb mixture. Bake at 400º for 45 minutes or until bubbly and brown.