Heat olive oil in a large pot over medium heat. Add chopped onion, carrot, and celery. Sauté until softened, about 5-7 minutes.

Add minced garlic and sauté for an additional minute until fragrant.

Add chopped fresh tomatoes, vegetable broth, salt, pepper, dried basil, and sugar to the pot. Bring to a boil.

Reduce heat and let simmer for 20-25 minutes, until the tomatoes are soft.

Using an immersion blender, blend the soup until smooth. Alternatively, carefully transfer to a blender in batches.

Taste and adjust seasoning if necessary. Serve hot, garnished with fresh basil if desired.