Preheat oven to 375. For the croutons, toss a little olive oil (1-2 tsp), salt, and pepper. Bake for 15 minutes.
For the soup, in a large pot heat a little oil. Saute the onion with a big pinch of salt for about 3 minutes.
Add the tomatoes with a little more salt and pepper. Cook for about 5 minutes, until soft and breaking apart.
Stir in the paste, sugar, then the broth. Bring to a boil then reduce heat to a simmer. Cook for another 5 minutes.
Add the basil then use a blender to blend it until smooth. Return to pan, stir in the vinegar. Simmer until ready to eat. Adjust salt anadpepper as needed
Add croutons and enjoy!.