Use any variety of apple you have on hand. Some will yield a softer result than others but they are all tasty. The only exception is perhaps the Granny Smith Apple which tends to end up with a very tough skin when baked.
Use your imagination and try other fruits such as peaches and pears.
Add some dates, raisins, cranberries to the center of the apple.
If you don't want the added sugar, try pouring a little juice in the bottom of the dish before cooking.
The coconut oil can be left out if you are avoiding added fat.