Combine beef, onion, and garlic in a skillet; cook over medium heat until browned, stirring well. Add tomatoes and next 7 ingredients, stirring well. Bring to a boil. Reduce heat; simmer, uncovered, 1 hour and 20 minutes or until sauce is reduced to 4 cups, stirring occasionally.
Cut zucchini in half crosswise; cut each half into 5 lengthwise slices. Coat with spray; place on baking sheets. Broil 5 1/2 inches from heat (with electric oven door partially opened) 6 minutes on each side.
Spoon 1 1/3 cups sauce in a 13- x 9- x 2-inch baking dish. Place half of zucchini slices over sauce, overlapping slightly. Spoon 1 1/3 cups sauce over zucchini; sprinkle with 2 tablespoons cheese. Place remaining zucchini over cheese; top with remaining 1 1/3 cups sauce, and sprinkle with remaining 1/4 cup cheese.
Bake, uncovered, at 350° for 25 minutes or until lightly browned and bubbly. Let stand 10 minutes before serving.