01 - Heat olive oil in a large pot over medium heat. Add diced onion and sauté for 4–5 minutes until translucent.
02 - Stir in garlic and cook for another 30 seconds until fragrant.
03 - Add crushed tomatoes, vegetable broth, tomato paste, sugar (if using), oregano, red pepper flakes, salt, and pepper. Stir well.
04 - Bring to a simmer and cook uncovered for 15–20 minutes to let the flavors meld.
05 - Remove from heat. Stir in fresh basil and heavy cream.
06 - Use an immersion blender to puree the soup until smooth, or carefully blend in batches using a regular blender.
07 - Return to low heat if needed and adjust seasoning to taste.
08 - Serve hot, garnished with extra basil and a drizzle of cream if desired.