Peel, core, and slice apples. Put them in the crockpot with the vanilla and cook on low for 8 hours. Stir every few hours. Once apples are very, very tender, mash with a potato masher and then stir in sugar and spices. Cook on low for another 6-7 hours, stirring occasionally.
Fully cool and pour into jars or an airtight container. Store in the refrigerator.
Recipe by I'm At Home Baking! at http://imathomebaking.com/crockpot-apple-butter/