Place the apples in a large slow cooker. Turn on to low.
In a medium sized bowl add the sugars, nutmeg, cinnamon, ginger,cloves and salt. Sprinkle this over the apples and stir it well to coat.
Cook on low in the slow cooker for 9-10 hours stirring occasionally. The mixture will thicken a little and turn darker brown. Stir in the vanilla and continue to cook on low uncovered for another two hours.
Turn off the slow cooker and let it cool for 1/2 hour. Use an immersion blender to puree it. Alternatively for a smoother apple butter you can also use a blender.
Spoon the apple butter into sterile jars and refrigerate for up to 14 days or freeze it!
Notes
Use this apple butter on scones, muffins, or various pork dishes.