Core, peel and finely chop the apples
Place apples in the slow cooker
Combine remaining ingredients and toss with the apples to coat
Cook on high for 1 hour.
Reduce heat to low and continue to cook for 10 - 12 hours, until the mixture turns dark brown.
Use an immersion blender to eliminate any lumps (or process in the blender in small batches)
Uncover and continue to cook for another 1 - 2 hours, or until the mixture begins to thicken.
Allow to cool.
Transfer apple butter to airtight containers and store in the refrigerator (or can it using the water bath method of canning)