Add the chopped apples, brown sugar, honey, apple cider, and salt to a large pot. Bring to a boil, stirring frequently, then reduce to a simmer and cover. Leave to cook for 1 ½ hours.
Transfer the apple mixture to a food processor or blender and blitz until smooth.
Return the blitzed mixture to the pot and add the cinnamon, ginger, and nutmeg. Simmer for another 30 minutes, until darkened and thickened, stirring frequently.
Stir in the vanilla extract and leave to cool completely. The apple butter will thicken further as it cools.
Use as desired, and transfer to an airtight container to store in the fridge for up to 3 months. You can also freeze leftovers.