Heat oil in large pot over medium; cook onion 5 minutes until soft and translucent.

Cook garlic 1 minute until fragrant, stirring constantly to prevent burning.

Add tomatoes, broth, sugar, salt, and pepper. Boil; reduce heat and simmer 15 minutes.

Immersion-blend smooth and creamy, or carefully transfer to blender in batches.

Add cream and basil; heat through 2-3 minutes without boiling.

Taste; adjust seasoning. Serve hot with optional basil and cream swirl.