Preheat your oven to 450°F (232°C). Halve the Campari tomatoes and place them in a large baking dish along with coarsely chopped onion and whole garlic cloves. Drizzle with olive oil and sprinkle with kosher salt, oregano, and smoked paprika. Toss everything together until evenly coated.

Transfer your baking dish into the preheated oven and roast for 30 to 40 minutes, stirring halfway through. The soup is done when the tomatoes are bursting and the onions are lightly browned.

Remove the vegetables from the oven and let them cool slightly. Transfer the roasted mixture into a large pot, add fresh basil leaves, and blend with an immersion blender until smooth.

Add vegetable broth until you reach your desired consistency and stir in the heavy cream. Let simmer over low heat for 5 to 10 minutes to allow flavors to meld.

Taste and adjust seasoning if necessary. If too acidic, add a pinch of sugar. Serve in bowls garnished with additional chopped basil.