Cut shortening into dry ingredients. Add wet and mix lightly. Roll out half into a 30 x 30 pan. Boil water, sugar and salt of filling. Add corn starch and water, boil for 5 minutes. Add apple and cinnamon and boil for a further 10 minutes. Pour over base. Roll our remaining pastry and cover. Bake at 180 C for 40 minutes to an hour Glaze with icing sugar, water and vanilla glaze.