This pie uses the crust from our Brown-Sugar Buttermilk Pie recipe. If you want to make both pies, prepare a double batch of dough, dividing it into 2 disks before chilling overnight or freezing up to 3 months.
As you're piling the apples in, you may think you have too many -- keep going. They elevate the top crust and will cook down. You'll need a large disk of dough for the top crust and a small one for the bottom. Make two batches of pate brisee: Resist the temptation to double the recipe (it won't work as well).
Room-temperature egg whites will produce the most voluminous meringue. For just the right texture, whip the whites until they hold stiff, glossy peaks -- but keep the mixture still spreadable enough that you can make decorative swirls in it as you top the pie.