Heat a large skillet over medium-high heat. Coat pan with cooking spray. Add beef to pan; sauté 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; sauté 4 minutes, stirring occasionally. Add garlic; sauté 1 minute, stirring constantly. Add beef; sprinkle with salt. Add flour; cook 1 minute, stirring frequently. Stir in milk, tomatoes, and cream cheese & red pepper flakes if desired, stirring until smooth; bring to a simmer. Cook 2 minutes or until thoroughly heated. Stir in pasta & parsley. Adjust seasonings.