Roast the peppers on a baking sheet in a 425 deg oven for about 40 min, turning every 10 min. Remove from the oven, place in a bowl and cover. Allow to cool, then peel, seed and dice. Set aside.
Heat the oil over medium heat in a large, heavy soup pot and add the onion. Cook, stirring often, until onion is translucent, about 3 minutes.
Add the carrot and celery and a pinch of salt. Cook, stirring often, until the vegetables are tender and fragrant, about 5 more minutes.
Add the garlic and cook, stirring, until fragrant, 30 seconds to a minute
Add the tomatoes (with their liquid if using diced tomatoes), the tomato paste, cinnamon and a pinch of salt. Cook over medium heat, stirring occasionally, about 10 minutes.
Add the diced roasted peppers, the vegetable broth, rice. Add fresh basil or basil essential oil. Bring to a boil, reduce the heat, cover and simmer 30 minutes, stirring from time to time.
Season with freshly ground pepper, taste and adjust salt. Remove the basil sprigs if you used fresh basil.
Using a handheld immersion blender, purée the soup, or use a traditional blender and purée in batches, then return to the pot.
Serve with toppings of choice such as: shavings of Parmesan cheese, croutons, a dollop of pesto, slivered basil, and/or a drizzle of olive oil