1Spray 1- to 1 1/2-quart slow cooker with cooking spray. In cooker, place all ingredients except bread.
2Cover; cook on Low heat setting 1 hour to 1 hour 15 minutes. Stir until cheese is smooth.
3Scrape down side of cooker with rubber spatula to help prevent edge of spread from scorching. Serve with bread slices. Spread can be kept warm on Low heat setting up to 3 hours; stir occasionally.