Heat olive oil in a large pot over medium heat.
Add the diced onion and sauté until translucent.
Stir in the minced garlic and cook for another minute.
Add the chopped tomatoes and sugar, stirring well.
Cook for about 5 minutes until the tomatoes soften.
Pour in the vegetable broth and bring to a boil.
Reduce heat and simmer for 15-20 minutes.
Use an immersion blender to puree the soup until smooth.
Season with salt and pepper to taste.
If desired, stir in heavy cream for added richness.