Place peeled, sliced apples in a large crockpot.
Add lemon juice, water, cinnamon, cloves, ginger, and nutmeg.
Cover and cook on high for 4-5 hours or until the apples easily fall apart into an applesauce-like consistently.
Add butter, vanilla, and salt and blend with an immersion blender until desired consistency is reached.
Add brown sugar or maple syrup to taste (I probably wouldn't add more than 1/2 cup, but that's me; a lot of it depends on what type of apples you used. Also, keep in mind that it will taste sweeter when it's cold, so less is more here.)
Serve warm or refrigerate until ready to use (you can refrigerate this up to a week or freeze it for several months.)