1. Preheat oven to 350°.
2. Place bread on a jelly-roll pan. Bake at 350° for 10 minutes or until crisp, stirring occasionally.
3. Preheat broiler.
4. Cut bell peppers in half lengthwise; discard seeds and membranes. Place pepper halves, skin sides up, on a foil-lined baking sheet; flatten with hand. Broil 10 minutes or until blackened. Place in a heavy-duty zip-top plastic bag; seal. Let stand 10 minutes. Peel; cut into 1-inch pieces.
5. Combine bread, bell peppers, and next 4 ingredients (through cucumber) in a large bowl. Combine vinegar and next 4 ingredients (through black pepper) in a small bowl. Gradually add oil, stirring with a whisk. Pour over bread mixture; toss.
6. Let stand 20 minutes or just until bread begins to soften. Sprinkle with basil.