Preheat your oven to 400°F (200°C).

Prepare vegetables by placing halved ripe tomatoes, quartered onions, and whole garlic cloves on a baking sheet. Drizzle with olive oil, and sprinkle with salt, pepper, and sugar. Toss to coat.

Roast the vegetables in the oven for 30 to 40 minutes until the tomatoes are soft and charred and the garlic is golden-brown.

Remove from the oven and let cool for a few minutes.

Transfer roasted vegetables to a blender and blend until smooth, adjusting as needed for texture.

Combine the blended mixture with broth in a large saucepan and stir well.

Bring the soup to a gentle simmer over medium heat, stirring occasionally for about 10 minutes.

Stir in heavy cream and fresh basil just before serving.

Adjust seasoning as needed, then ladle into bowls and serve with crusty bread.