Place the applesauce, granulated sugar, brown sugar, cinnamon, cloves, nutmeg, apple cider vinegar, and pinch of salt into the crockpot. Stir everything together until the sugars and spices are evenly distributed throughout the applesauce.
Set your crockpot to low and let the mixture simmer gently for about 6-8 hours. Stir occasionally, until the applesauce turns a caramel color.
About 30 minutes before your apple butter is ready, add the teaspoon of vanilla.
Using an immersion blender, carefully blend the apple butter mixture until smooth.
Place lid back on slow cooker leaving it slightly ajar to allow enough room for steam to escape. Cook on low for another 2-3 hours, stirring occasionally, until the sauce has thickened, and has become dark brown in color.
Once your apple butter has reached the perfect consistency, turn off the crockpot and let it cool.
If canning, ladle hot apple butter into hot, sanitized jars, and process in boiling water bath for 10 minutes (adjusting for your altitude). If not canning, allow apple butter to cool for a few hours, then place in clean jars and refrigerate.