In the bowl beat the butter, shortening and sugar until smooth ( 2-3 minutes ). Beat in the vanilla and lemon zest.
Gently stir in the flour just until incorporated.
Flatten the dough into 4 disks ( you will need 2 for this recipe ), wrap in plastic wrap, and chill the dough until firm but not hard ( 30-40 minutes ).
Peel and grind the apples on cheese grinder.
Put in a saucepan with sugar, cinnamon and vanilla, stir all the time for 10-15 minutes. Let cool completely.
Roll half dough between two pieces of parchment paper, take the top paper off and second pies paper with rolled dough put into the baking dish (9-11 inches)
Put apple mixture on the dough and cover with another piece of rolled dough but this time without paper. If you find an apple to moist add ground almond, walnut or just plain bread crumbs just don't make to dry.
Make some holes with the fork.
Bake 25-30 minutes on 350F.
Let cool, and you can serve sprinkled with icing sugar.
If you leave overnight it tastes even better and it is easier to cut.