Quarter the apples, leaving the seeds and skins intact. Add apples into a large pot with 4 cups of water and cover with a lid. Cook over medium-high heat for 20 minutes, remove the lid, and stir. You will need to occasionally check the water level to make sure the water has not completely evaporated and the apples are not sticking to the pot. If they do begin to stick, add 1/2 cup more water at a time. Place the lid back on and continue cooking the apples until they are mushy, checking every 5 minutes to make sure the apples are not sticking, about 1 hour total. You do not want too much liquid in the pan by the end of the cooking process. If you have too much liquid and the apples are mushy, remove lid and cook for 2 more minutes until the liquid evaporates.
Using a food mill over a bowl, pour the cooked apples in a little at a time and mill into the bowl, removing seeds and skin as needed, until everything has been milled. At this point, you have applesauce. Season as desired with vanilla, cinnamon, or maple syrup. Just a touch of cinnamon and a pinch of salt will bring out all the flavors.