Slicing the apples. Peel the apples and core them. Slice them into solid slices -- not so thin that they look like paper, and not so thick that you cannot wrap your mouth around them. Put all the slices into a large bowl.
Making the apple mixture. Cover the apples with the sugar and stir. Slice the vanilla bean down the middle and scrape out the paste from the inside of it. Put that paste in with the apples and sugar, then cut the shell of the vanilla bean into small strips and let those fall into the apples as well. Cover the apples with the cinnamon, nutmeg, allspice, lemon juice, and brandy. Stir well, making sure to coat each of the apple slices. Set the bowl aside to let the apples marinate in these juices for at least 2 hours before making the pie.