01 - Preheat oven to 375°F. In a mixing bowl, toss bread cubes with melted butter, olive oil, and garlic powder until evenly coated. Spread on a baking sheet in a single layer and bake for 10-12 minutes, turning once, until golden brown and crisp. Remove from oven and set aside.
02 - In a large saucepan over medium heat, sauté diced onion in a tablespoon of olive oil for 3-4 minutes until translucent. Add garlic and cook for 1 minute until fragrant.
03 - Add chopped tomatoes, vegetable broth, salt, and pepper to the pot. Bring to a simmer. Cook uncovered for 20 minutes, stirring occasionally, until tomatoes are soft and breaking down.
04 - Remove saucepan from heat. Stir in chopped basil. Using an immersion blender, puree the soup until velvety and smooth. Alternatively, blend in batches using a countertop blender and return to pot. Stir in heavy cream and gently reheat over low heat without boiling.
05 - Ladle soup into warmed bowls. Top each serving with croûtons and a sprinkle of fresh basil. Serve immediately.