Combine the butter, shortening, 2 cups of the cake flour, and 1 cup of the all-purpose flour. Blend together. Stop mixer, scrape the sides and add remaining 2 cups of cake flour and remaining 1 cup of all purpose flour. Blend to combine completely. Mix sugar and salt into 1/4 cup of the water and add it to the flour mixture. Blend briefly and add the remaining water if needed. The dough should not be overworked and should make a solid piece when held in your hand. Turn the dough out onto a lightly floured smooth surface and knead it several times. Divide the dough into portions and flatten it. Wrap unused dough in plastic. Roll out the dough to fit a 9-inch pie pan.
Preheat oven to 475 degrees F. Prick bottom and sides of pastry with fork. Bake 12 minutes or until light brown. Cool on wire rack.
Recipe courtesy of Shirley Rooney