Heat oven to 400°F. Line cookie sheet with foil.
Place torn bread in food processor or mini chopper; pulse until bread crumbs form. Place in shallow dish.
Place bacon pieces in bread crumbs. Sprinkle small amount of crumbs over top; press down so crumbs stick. Place bacon pieces on cookie sheet.
Bake 10 minutes.
Remove bacon from cookie sheet to large platter. Sprinkle each piece with tomato and lettuce. Drizzle each with mayonnaise. Serve immediately.