Wash, peel, and core the apples. Then, chop them into chunks.
Place the apple chunks in your slow cooker.Add both types of sugar, ground cinnamon, ground cloves, ground nutmeg, and a pinch of salt to the apples.
Stir everything together until the apples are well-coated with the sugar and spices.Cover the slow cooker and cook on low for 8 hours or until the apples become soft and can be easily mashed.
Use an immersion blender or transfer the mixture to a regular blender to blend until smooth.Return the blended mixture to the slow cooker and cook for an additional 1-2 hours, uncovered, to thicken the apple butter.
Taste and adjust the sweetness and spices if needed.Once the apple butter reaches your desired consistency, let it cool.
Store it in sterilized jars in the refrigerator.