Spray 13x9-inch (3-quart) glass baking dish and 16x12-inch sheet of foil with nonstick cooking spray. Set aside.
Cook ziti in Dutch oven or large saucepan as directed on package. Drain in colander. Cover to keep warm; set aside.
Meanwhile, in large skillet, cook ground beef and onion over medium heat until beef is thoroughly cooked, stirring frequently. Drain. Stir in pasta sauce and cinnamon. Bring to a boil. Reduce heat; simmer 10 to 12 minutes or until slightly thickened, stirring occasionally.
Heat oven to 350°F. In same Dutch oven, combine 1 cup of the milk, flour, salt and pepper; mix with wire whisk until smooth. Stir in remaining 2 cups milk. Cook over medium heat until mixture boils and is slightly thickened, stirring constantly. Boil 1 minute, stirring constantly. Remove from heat.
Beat eggs in medium bowl with wire whisk. Gradually add half of hot milk mixture, stirring constantly. Stir egg mixture back into mixture in dutch oven. Add cheese; mix well. Add cooked ziti; toss gently to coat evenly.
Place half of ziti mixture in sprayed baking dish. Spoon beef mixture evenly over ziti mixture. Top with remaining ziti mixture. Cover tightly with sprayed foil.
Bake at 350°F. for 35 to 40 minutes or until edges are bubbly. Meanwhile, in small bowl, mix bread crumbs and butter.
Remove foil; sprinkle bread crumb mixture over top. Bake uncovered an additional 5 minutes. Let stand 5 minutes before serving.