01 - Melt butter in a large pot over medium heat. Add chopped onion and diced carrot, sauté for 5 minutes until softened.
02 - Add minced garlic and cook for 1 minute until fragrant.
03 - Stir in tomato paste, canned tomatoes with juices, vegetable broth, sugar, dried basil, dried thyme, bay leaf, salt, and pepper. Bring mixture to a simmer.
04 - Reduce heat, cover pot, and cook for 20 minutes, stirring occasionally.
05 - Remove bay leaf. Purée soup until smooth using an immersion blender or blend carefully in batches in a countertop blender.
06 - Return soup to low heat, stir in heavy cream, and heat gently for 2-3 minutes. Adjust seasoning as needed.
07 - Ladle soup into bowls and garnish with fresh basil leaves and a swirl of cream, if desired.