01 - Preheat oven to 400°F. Cut the top off the garlic head, drizzle with 1 teaspoon olive oil, wrap in foil, and place on a baking tray with quartered tomatoes. Drizzle tomatoes with 1 tablespoon olive oil, season with salt and pepper. Roast for 35 to 40 minutes until tomatoes are soft and garlic is golden.
02 - Heat 1 tablespoon olive oil in a large pot over medium heat. Sauté chopped onion for 5 to 7 minutes until translucent.
03 - Toss bread cubes with 2 tablespoons olive oil, Italian herbs, and 1/4 teaspoon salt. Spread on a baking sheet and bake in oven for 10 to 12 minutes, tossing once, until golden and crisp. Set aside.
04 - Squeeze roasted garlic cloves from skins. Add garlic and roasted tomatoes with their juices to the pot with onions. Stir in vegetable broth and bring mixture to a simmer for 10 minutes.
05 - Stir in fresh basil leaves and sugar if using. Remove pot from heat.
06 - Use an immersion blender or transfer in batches to a blender and puree soup until smooth. For a silkier texture, strain through a fine mesh sieve.
07 - Stir in heavy cream or coconut milk if desired. Adjust seasoning with additional salt and pepper to taste.
08 - Ladle soup into bowls, top with croutons and extra fresh basil leaves.