Peel apples, if desired, and remove cores and seeds. Cut each apple into 8 pieces. Place apples in a large, heavy saucepan along with cider, cinnamon sticks, allspice, and nutmeg. Cover and bring to a boil over medium-high heat, stirring occasionally, and cook for 30 minutes. Reduce heat to medium-low and continue to cook, covered and stirring frequently, until apples have completely broken down into a thick sauce, about 30 minutes longer. Add sugar to taste and, if desired, add Calvados and cook for 10 minutes longer. Pass applesauce through a food mill or a coarse sieve to remove any remaining skins and solids. Discard solids. Set sauce aside to cool, or enjoy warm.