Marion's Apple Butter

This recipe is from Preserving the Harvest by Carol Costenbader. I made it last night using the oven method. I also used the smallest amount of sugar and it worked fine! Next time I will try it in my slow cooker - just need to decide on high vs. low.
This is YUMMY!!!

Ingredients
10 large tart apples (about 5 lbs)
2 cups apple cider
3-5 cups sugar
3/4 tsp. ground cloves
1/2 tsp ground all-spice
3 tsp. ground cinnamon
1/2 tsp. ground nutmeg

1. Process
2. Wash, core & quarter apples.
   
3. Combine apples and cider in oven safe pot on top of stove.
   
4. Cook slowly in cider until tender.
   
5. Blend in a food processor or run through a food mill.
   
6. Return apples to pot.
   
7. Add sugar and spices and stir to combine.
   
8. 
9. Cook in 350°F oven or slow cooker 6-8 hours, stirring often. Test for desired thickness by spooning mixture onto a cold plate. If no liquid oozes around edges, it is thick enough. Ladle into jars. Process 10 minutes or freeze.