Heat oven to 350°F. Spray 12x8-inch (2-quart) baking dish and 14x12-inch sheet of foil with nonstick cooking spray. Set aside.
In Dutch oven or large saucepan, cook ziti to desired doneness as directed on package. Drain; return to Dutch oven. Cover to keep warm.
Meanwhile, in medium saucepan, combine eggplant, onion, tomato sauce, cinnamon and oregano; mix well. Bring to a boil. Reduce heat; simmer 10 to 15 minutes or until onion and eggplant are crisp-tender, stirring frequently.
In another medium saucepan, combine 1/2 cup of the milk, flour, salt and pepper; mix with wire whisk until smooth. Stir in remaining 1 1/2 cups milk. Cook over medium heat until mixture boils and thickens, stirring constantly. Boil and stir 1 minute. Remove from heat.
In medium bowl, beat eggs; gradually add half of the hot milk mixture to beaten eggs, stirring constantly. Stir egg mixture back into mixture in saucepan. Add cheese; mix well. Add to cooked ziti; toss gently to coat evenly.
Place half of ziti mixture in sprayed dish. Spoon tomato sauce over ziti. Top with remaining ziti mixture. Cover tightly with sprayed foil.
Bake at 350°F. for 35 to 45 minutes or until casserole is bubbly. In small bowl, combine bread crumbs and melted margarine; mix well. Sprinkle over top; bake uncovered for an additional 5 minutes. Let stand 5 minutes before serving.