Core, peel and chop the apples into bite sized pieces.
Place the apples in the slow cooker.
Mix together the remaining ingredients and pour over the apples.
Cook on high for 1 hour.
Reduce to low and cook for 10-12 hours until the mixture turns a dark brown.
Use an immersion blender to remove any lumps or process in the blender in batches.
Leave uncovered and cooking for 1-2 hours until the mixture thickens.
Allow to cool.
Transfer apple butter to airtight containers and store in the refrigerator.