Heat olive oil in a saucepan over medium heat. Add chopped onion and sauté until translucent.

Add minced garlic and cook for another minute until fragrant.

Stir in the crushed tomatoes, vegetable broth, sugar, salt, and pepper. Bring to a boil.

Reduce heat and let it simmer for 20 minutes, stirring occasionally.

Use a blender to puree the soup until smooth. Return to the saucepan.

Stir in heavy cream if using, and heat through.

Serve hot, garnished with fresh basil.