Cook pasta according to package directions, omitting salt and fat.
Drain.
Heat a large skillet over medium-high heat. Coat pan with cooking spray.
Add beef to pan; saut 5 minutes or until browned, stirring to crumble.
Remove beef from pan; drain. Wipe pan clean with paper towels.
Add oil to pan; swirl to coat.
Add onion; saut 4 minutes, stirring occasionally.
Add garlic; saut 1 minute, stirring constantly.
Add beef; sprinkle with salt.
Add flour; cook 1 minute, stirring frequently. Stir in milk, tomatoes, and cream cheeses, stirring until smooth; bring to a simmer. Cook 2 minutes or until thoroughly heated. Stir in pasta.
Spoon pasta mixture into a 13 x 9-inch broiler-safe baking dish coated with cooking spray.
Sprinkle mozzarella evenly over top. Broil 4 minutes or until golden.