A tip I got at joyofbaking.com is to prepare the apples as usual but sprinkle them with the spices & sugar & let the apples sit for a few hours & they'll release their juices.
Then drain the juices off & boil the liquid down with some butter. Pile the apples & the reduced juices into the crust & make sure the top crust is well vented.

The problem is that the apples are juicy & as they bake they release the juice & shrink. The above procedure will prevent the gap.

Thanks, Ginger! Yes, I did get alot of juice that came out of the pie when I baked it. Thank God for tin foil! lol I've never heard of letting the apples and spices sit and then boiling down the liquid. How long do you suggest to boil and how much butter?

Sprinkle the apples with a little fresh lemon juice before you add the sugar to help them not turn brown. If you use a lot of apples, add maybe 1 1/2 to 2 TBL butter when you boil the juice mixture down to about 1/2 the original amount.

I've had really good luck using granny smith apples for my apple pies. They seem to hold their shape and size very well.

Tracey

I agree with tracey. I use either Granny smith or spies, but my favorite is a nice tart Macintosh. They don't shrink much and they are super for baking or eating.