For the vinaigrette, whisk ingredients together. Set aside.
Heat oil in a large sauté pan. Add bread and salt. Cook over low to medium heat, tossing frequently, for 10 minutes or until nicely browned. Add more oil as needed.
In a large bowl, mix tomatoes, cucumber, bell peppers, red onion, basil, and capers. Add bread cubes and toss with vinaigrette.
Season liberally with salt and pepper. Serve, or allow the salad to sit for about half an hour to allow the flavors to blend.