Heat oil in a Dutch oven or heavy stockpot over medium-low heat; cook and stir onion and garlic in hot oil until tender, about 5 minutes. Add tomatoes to onion mixture, crushing with a potato masher. Stir bread, basil, and brown sugar into tomato mixture and simmer until bread is completely saturated and starts to break down, about 10 minutes.
Pour tomato mixture into a blender no more than half full; add butter. Cover and hold lid down; pulse a few times before leaving on to blend. Puree in batches until smooth. Return pureed soup to Dutch oven over medium heat; add broth and simmer until heated through, about 5 minutes. Season soup with salt and pepper.
I recommend using home-canned tomatoes.
Substitute 1 tablespoon dried basil for the fresh basil, if desired.
Source: Read Full Article