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