Normally, I’m not a fan of purchased pie crust, and you certainly can make your own. As a matter of fact, this would be a good place for a gluten-free press-in-place crust. (I find gluten-free crusts just don’t roll out well for me.) And if you want the cookie to be gluten-free, of course substitute a gluten-free flour in the streusel.
These make the most adorable little individual apple pies – the recipe’s from lovelylittlekitchen.com.