Any ideas on what to do with a mountain of apples, other than apple pie?
Apple butter, apple sauce, dehydrated apple rings, apple juice, baked apples, freeze apples in portions that fit your pie.
Canning some chutney would be nice. I also like to throw apples in any dish with sweet potatoes, onions, pumpkin or carrots (think velvety soups). And if you want a break from apple pie for dessert, there is a whole other world of crisps, grunts, brown betties, and cakes that is worth exploring.
Apple ice cream!
If you truly have a mountain of apples you can juice and ferment them to make delicious hard apple cider. It is much easier than beer or wine making and a great way to preserve (and add value to) your apply abundance.
This site covers the basics. http://makinghardcider.com/
Apple strudel, apple fritters, apple slices with a yogurt-cinnamon dip....
Apple cakes, especially those made with oil freeze really well. I'm thinking of a classic "jewish apple cake," the recipe for which I do not have on hand, but this seems very close (mine does not have nuts, and I end off with batter, not apples): http://smittenkitchen.com...
Apple muffins or quick breads would also be good for freezing. You can also just slice some and out them in a jar with sugar and cinnamon and a touch of vanilla so that they macerate. The use them to top oatmeal, yogurt, or anything else you like.
And "Judy Rogers' Roasted Applesauce" is highlighted in my side bar, so that and other apple recipes here are worth checking out.