Gather all ingredients.
Place tomatoes and juice in a stockpot over medium heat; bring to a simmer. Cook until tomatoes have softened, about 30 minutes.
Remove the pot from heat. Add basil leaves to the pot.
Use an immersion blender to purée soup until smooth.
Stir in heavy cream and butter. Cook and stir over medium heat until butter is melted, about 5 minutes. Do not boil. Season with salt and pepper.
Serve hot and enjoy!