Spray inside of 1- to 2 1/2-quart slow cooker with cooking spray.
Place all ingredients except bread in cooker.
Cover and cook on low heat setting 1 to 1 1/4 hours (or high heat setting 30 to 45 minutes) or until cream cheese is melted. Stir until cheese is smooth.
Scrape down side of cooker with rubber spatula to help prevent edge of spread from scorching. Turn to low heat setting.
Serve with bread slices. Spread will hold up to 3 hours.