Add the chopped apples to a 6-quart slow cooker. In a separate bowl, combine the sugar, cinnamon, ground cloves, and salt. Sprinkle the mixture over the apples and stir thoroughly to ensure the fruit is evenly coated in the fragrant, spiced sugar.

Secure the lid and cook on high for 1 hour. Afterward, reduce the heat to low and continue cooking, covered, for 9 to 11 hours. Stir occasionally throughout, increasing frequency as the mixture thickens and darkens to a deep amber hue, to prevent sticking or burning along the edges.

Once the apple mixture reaches a rich, thick consistency, uncover and cook for an additional hour on low heat to concentrate the flavor further. For a smoother texture, whisk vigorously or use an immersion blender to create a silky finish.

Ladle the finished apple butter into freezer-safe containers, leaving about 1/2 inch of space at the top to allow for expansion. Seal tightly, then refrigerate or freeze until ready to use.