Add all ingredients to a large pot and stir to combine. Cover and cook on med-low heat for about 1 hour (or until apples are basically like mush).
Pour into a large bowl and puree using an immersion blender until there are no chunks (you can also use a food processor if you don’t have an immersion blender, but you might have to do it in batches).
Add the apple puree back to the pot and place on the stove. Turn the stove onto medium heat and bring the apples to a simmer. Reduce heat to low and cook uncovered for at least 1 hour (you want the puree to thicken and reduce). Stir occasionally. (Be careful of some splashing that can occur when it is on the stove).
Remove from heat and put into a storing container. Allow to cool before covering and place in fridge. Will keep in the fridge for up to 3 weeks.