Melt the butter in a Dutch oven pot over medium heat. Once the butter has melted, add the garlic, dried basil, and red pepper flakes, then sauté until the garlic starts to golden.
Add the canned tomatoes and pepper, then mix well.
Bring the soup to a boil while stirring occasionally. Then cover and simmer for 20 minutes, continuing to stir every now and then.
After the first 20 minutes, remove the lid slightly to allow steam to escape and simmer the soup for another 25 minutes. At the end of the time, add the basil leaves and stir.
Blend with an immersion blender until smooth.
Serve the soup with fresh basil leaves, black pepper, and a dash of cream.
