Preheat your oven to 450°F (230°C). Halve the sweet Campari tomatoes and place them in a large baking dish with coarsely chopped onion and whole garlic cloves. Drizzle everything with olive oil, then sprinkle with kosher salt, oregano, and smoked paprika. Roast for 30–40 minutes, tossing halfway through, until the vegetables are caramelized and lightly browned.

Once the roasted vegetables have cooled slightly, transfer them to a large pot. Add a handful of fresh basil to the mix. Using an immersion blender, blend the mixture until you achieve a velvety smooth texture.

Stir in the vegetable broth to achieve your desired consistency and add the heavy cream. Taste your soup and adjust the seasoning with additional salt if needed.

Ladle the soup into bowls and garnish each with additional basil leaves. Serve with a crispy grilled cheese sandwich or a side salad.