12 ounces ziti pasta 1 small yellow onion, chopped 1 tablespoon olive oil 2 garlic cloves, minced 1 1/2 pounds lean ground beef 2 (15-oz.) cans tomato sauce 1 tablespoon fresh lemon juice 1 1/2 teaspoons dried oregano 1 teaspoon sugar 1/2 teaspoon ground cinnamon 1 1/2 teaspoons kosher salt, divided 3 tablespoons butter 3 tablespoons all-purpose flour 3 cups milk 1 cup grated Parmesan cheese 1/2 teaspoon freshly ground black pepper Vegetable cooking spray 1 (8-oz.) package shredded mozzarella cheese 1/3 cup fine, dry breadcrumbs