01 - Preheat oven to 425°F. Place red bell peppers on baking sheet and roast for 20 to 25 minutes, turning occasionally, until skins are blistered and charred.
02 - Transfer roasted peppers to a bowl and cover with plastic wrap. Let steam for 10 minutes. Peel off skins, remove seeds, and roughly chop.
03 - In a large pot, heat olive oil over medium heat. Add chopped onion, sliced carrot, and minced garlic; sauté for 5 to 6 minutes until softened.
04 - Add chopped roasted peppers, diced tomatoes with juices, smoked paprika, dried thyme, salt, and pepper. Cook for 5 minutes, stirring occasionally.
05 - Pour in vegetable broth. Bring to a boil, then reduce heat and simmer uncovered for 15 minutes.
06 - Remove from heat. Purée the soup using an immersion blender or in batches with a countertop blender until smooth.
07 - Stir in heavy cream and warm gently over low heat for 2 to 3 minutes without boiling. Adjust seasoning as needed.
08 - Ladle into bowls and garnish with fresh basil leaves and croutons if desired. Serve hot.