Wash, quarter and core out the apples but try leaving the skin on for body and flavor.
Zest and juice the lemon, adding both to a large sauce pan with the apples and cinnamon.
Cover and cook slowly over medium heat, mashing occasionally for 30-35 minutes.
Puree through a food mill, return apples to the pan, add the sugar to taste while simmering slowly.
Cook until texture is thick enough o hold shape firmly in a large spoon. Season with the vanilla.