Put the butter, sugar, vanilla seeds, if using, and the salt into the bowl of an electric stand mixer and beat together until fluffy and pale in colour. Slowly add the beaten eggs, a little at a time, beating well after each addition.
Sift the flour over the creamed mixture, then slowly mix in the flour until the pastry comes together, being careful not to over mix. (If you prefer, the pastry can be made by hand without a mixer, using a wooden spoon to beat and combine the ingredients, as directed.)
Turn the pastry on to a lightly floured work surface, but do not knead the pastry, just push it together. This recipe makes about 600g pastry and you can either use it all or freeze some to use at a later date. It's unwise to make this recipe in a smaller quantity and you can easily freeze half of it (or as much as you have leftover) to use another time
Wrap the pastry in cling film (either wrap it as one piece or divide it into two pieces and wrap each piece separately) and then leave it to rest in the fridge for 30 minutes before rolling out. (I like to shape the pastry into flat even square (s) so that they fit comfortably into my fridge or freezer.) Freeze the pastry you are not using an use within 3 months. Defrost overnight in the fridge before use.