Chop the onion, carrot, and garlic.
In the slow cooker, combine the crushed tomatoes, onion, garlic, and carrot.
Add the vegetable broth, dried basil, and oregano.
Season with salt and pepper to taste.
Stir all ingredients until well mixed.
Cover the slow cooker and set it to low heat.
Cook for 6-8 hours, or until the vegetables are tender.
Once done, use an immersion blender to puree the soup until smooth.
If desired, stir in the heavy cream for extra richness.
Serve hot, garnished with fresh basil leaves.