Preheat the oven to 400℉.
On a large baking sheet, combine the tomatoes, fennel, onion, garlic, olive oil, balsamic vinegar, salt, pepper, red pepper flakes, smoked paprika, cumin and thyme and toss until well combined. Spread into an even layer and transfer to the oven and roast for 45 minutes.
With about 10 minutes left on your cook time, heat a large pot or dutch oven over medium heat. Add the broth, can of tomatoes and roasted red bell peppers and bring to a light simmer.
When the cook time is complete, carefully transfer the roasted veggies and any of it’s juices to the pot. Using an immersion blender, blend until smooth. Alternatively, you can blend the soup in a high-speed blender in batches. Taste and adjust seasonings, if desired.
To serve, ladle into bowls and garnish with a drizzle of olive oil, fennel fronds, and a few cracks of freshly ground black pepper.