Preheat the oven to 400 degrees F.
Cut the tomatoes into chunks and then toss with the olive oil, garlic, salt, and pepper.
Roast in the oven for 40 minutes.
Once the tomatoes are almost done roasting, melt the butter in a large soup pot. Add the onions and cook until softened and translucent, about 5-7 minutes.
Add the garlic and cook another minute.
Add the roasted tomatoes, crushed tomatoes, basil leaves, and broth, and stir to combine.
Bring to a simmer and cook for 20 minutes.
Using an immersion blender or stand blender, puree the soup.
Stir in the heavy cream. Season with additional salt and pepper, to taste.
Serve and enjoy!