Spray inside of 1- to 1 1/2-quart slow cooker with cooking spray. In slow cooker, mix all ingredients except bread slices, additional green onions and bell pepper.
Cover; cook on Low heat setting 2 to 3 hours or until hot.
Meanwhile, heat oven to 315°F. Line cookie sheet with foil. Place bread slices on cookie sheet; lightly spray bread with cooking spray.
Bake 6 to 9 minutes or until crisp. Remove from cookie sheet to cooling rack.
Before serving, stir until dip is well blended and smooth. Top with green onions and bell pepper. Serve with toasted bread slices. Dip can be held on Low heat setting up to 1 hour.