Heat over medium heat, stirring constantly, until all ingredients are thoroughly combined and the mixture is warm and starting to bubble. Dip will seem very thin, but will thicken considerably as it cools.
Serve warm with fresh apples.
Store leftover dip in an airtight container in the refrigerator for up to a week. To reheat, place in the microwave for about 30-45 seconds, or until warmed through.