In a large pot, heat olive oil over medium heat. Add chopped onion and sauté for 5-7 minutes until softened and translucent.

Stir in minced garlic and let it cook for another minute until fragrant.

Pour in crushed tomatoes and vegetable broth, then add dried basil, sugar, salt, and black pepper. Bring to a boil, then simmer uncovered for 15-20 minutes.

Carefully remove pot from heat. Blend the soup until smooth using an immersion blender.

Return pot to low heat and stir in heavy cream until fully combined. Taste and adjust seasoning as needed.

Ladle the soup into serving bowls and garnish with fresh basil leaves if desired.