In a 3-quart slow cooker, add the whole tomatoes, tomato puree, tomato paste, garlic, onion, carrots, parmesan cheese, basil, and oregano. Stir to combine. Cover and cook on low for 6-8 hours.
Using an immersion blender, puree the sauce to your desired consistency. Taste and season with salt and pepper to taste.
If adding meat, cook the ground meat in a nonstick skillet over medium-high heat until browned and fully cooked. Drain and add to the pureed sauce; allow to cook on low for about another 30 minutes before serving.
