I made an apple pie beer last year at my wife's request. It was not good.
I made a 4 gallon batch with 6lbs of lme, 1/2lb crystal 60, 1/2lb flaked oats, 1/2 lb biscuit, 1/2lb maltodextrin. 1/2oz ekg at :60, 1/2 oz ekg at :15, cinnamon, nutmeg, vanilla and 1 gallon fresh apple cider after chilling.
It was flat and lifeless. Nice apple aroma, but just sorta off.
I would recommend a similar beer and cider in a snakebite to get the apple pie effect.
I did make a float with ice cream made with my vanilla stout and the apple pie beer. That was pretty good. Kinda like an apple pie a la mode