Wash and dry the tomatoes, and then slice them in half. Remove the wet pulp and seeds from ⅔ of the tomatoes and discard.
Finely chop the tomatoes and place them in a mixing bowl.
Add the garlic, oil, vinegar, salt, and black pepper to the bowl.
Tear the basil by hand into small pieces and add them to the bowl.
Stir the mixture until well combined. Taste, adjust for salt and pepper and, if the tomatoes used aren't very sweet, add an optional pinch of sugar if desired.
Cover and refrigerate for 30 minutes to allow the mixture to develop more flavor.
Serve immediately. Bruschetta is best eaten fresh, but leftovers can be refrigerated for up to 3 days.