01 - Heat the olive oil in a large pot over medium heat. Add the chopped onion and sauté for 4–5 minutes until soft and translucent.
02 - Add the garlic and cook for 1 minute until fragrant.
03 - Stir in the tomatoes (with juices if using canned), vegetable broth, sugar, salt, pepper, and dried basil if using. Bring to a simmer.
04 - Cover and cook for 15 minutes, stirring occasionally, until the flavors are well combined and the tomatoes have broken down.
05 - Remove from heat. Use an immersion blender to puree the soup until smooth, or carefully blend in batches in a countertop blender.
06 - Return the soup to low heat. Stir in the heavy cream and heat gently for 2–3 minutes without boiling. Adjust seasoning if needed.
07 - Ladle into bowls, garnish with fresh basil and a drizzle of cream if desired. Serve hot.