Blend first 5 ingredients in processor until basil and olives are finely chopped. Season dressing with salt and pepper. (Can be prepared 1 day ahead. Cover and chill.)
Cut bread horizontally in half. Pull or cut out enough interior bread to leave 1-1/2-inch-thick shell. spread half of dressing on cut side of bottom bread shell. Layer with half each of salami, cheese, peppers, onions and tomatoes. Repeat with remaining salami, cheese, peppers, onions and tomatoes. Spread remaining half of dressing on cut side of top bread shell; press onto filling. Wrap tightly in plastic; chill at least 1 hour. (Can be made 1 day ahead. Keep chilled.)
Place muffuletta on platter. Cut into wedges and serve.