I did this for the first time this week with some extra apples I had laying around. I will never buy applesauce from the store AGAIN after doing this.
What you need:
5 large apples, peeled and cored (I used Honeycrisp because they are big and sweet)
1 Tablespoon brown sugar (I added a little more later, so probably 2 Tablespoons total)
1/2 Teaspoon cinnamon
1 Teaspoon vanilla extract
1/4 cup water
Cook for a few hours in the crockpot until the apples are soft. Mash them up however you like them. I like mine extra chunky :)