Preheat oven to 450° and line a large sheet pan with parchment paper.
Cut tomatoes in quarters and place on the prepared baking sheet in a single layer. Drizzle with the oil, and bake in the preheated oven for 30 minutes. Remove from oven and set aside to cool slightly.
Add the butter to a medium Dutch oven or soup pot, and melt over medium heat. Once melted, add the onions and saute for 4-5 minutes, or until translucent and starting to brown. Add the garlic and saute another minute.
Add the broth, basil, salt, sugar, pepper, smoked paprika, and roasted tomatoes to the pot. Stir to combine, and bring to a simmer. Once simmering, cover and cook at a low simmer for 30 minutes.
After 30 minutes, remove from heat. Carefully blend the soup using an immersion blender until smooth. Alternatively, you can batch blend it in a regular blender. (Be careful because the soup will be hot!). Serve!