When you find yourself with this many apples (and some giant lemons) baking with them is always a good choice.
Julia and Jacques Cooking at Home to made a few rustic apple tarts.
Fold up the edges, pinching them together gently as you go around. Place a few thin slivers of unsalted butter on top of the apples and place the tarts in the oven. Bake for one hour, until crust is nicely browned.
This is a great recipe not only for apples, but for apricots, peaches, nectarines, or any other stone fruit.