4 to 6 cups sifted all-purpose flour, plus more for dusting
Preheat the oven to 350 degrees F.
Begin by creaming the butter and sugar in a large mixing bowl. Add the salt to the first cup of flour and mix with the butter mixture by stirring in using a wooden spoon. Add the flour slowly until the mixture can be worked by hand, then place the mixture on a board or counter that has been lightly dusted with flour to avoid sticking. Dust your hands with flour, then work the flour into the butter mixture until it begins to crumble and not hold together.
Now, place the mixture on a heavy steel baking pan or cookie sheet, and spread out to cover the pan entirely. Prick all over with a fork. Bake until golden brown, about 25 minutes. Let cool. Cut immediately.