Heat oven to 350 F. In a large bowl, combine ground beef and all ingredients, mixing lightly but thoroughly (do not pack). Gently shape mixture into twelve meatballs. Place on a broiler pan. Bake in a 350 oven 25-30 minutes or until done.
Heat oil in a medium saucepan on medium-high heat until hot, saute onion and garlic until translucent, about 3-4 minutes. Add tomatoes, basil, oregano, parsley, salt and red pepper flakes; stir to combine. Lower heat and simmer 45 minutes, stirring occasionally.
Remove from heat, allow mixture to cool. Using an immersion blender or food processor, blend to desired consistency.
Combine meatballs and marinara sauce in a large saucepan; heat thoroughly, stirring occasionally. Serve over spaghetti; sprinkle with Parmesan cheese if desired.
Nutrition information per serving: Calories 480; Total fat 20g (Sat. fat 6g; Trans fat 0g); Cholest. 75mg; Sodium 1340mg; Total Carb. 40g; Fiber 4g; Total Sugars 7g; Protein 32g; Vit D (0% DV); Calcium (10% DV); Iron (30% DV); Potas. (20%DV)