Combine 5 1/2 c. flour, 1 1/2 c. shortening (Crisco) and 1 t. plus 20 shakes of salt. Work together with fingers til dough "sticks" and add 1 t. baking powder and 1/4 c. sugar; mix in. Mix 1 egg and 1 c. condensed milk. Add to batter and mix til it resembles pie dough. Divide in half and roll out 1 piece to fit a (10x15 inch) jelly roll pan. Peel and core 3 1/2 to 6 lbs. Macintosh or Granny Smith apples and slice 1/4 inch thick. Cut into triangle shapes. Cover the bottom crust with the apples til level with the edge of the jelly roll pan. Sprinkle with 1 c. sugar (if apples are sour add more sugar, if apples are too sweet add lemon juice). Sprinkle with cinnamon, then 2 T. flour or tapioca and top with 9 pats of butter. Cover with top crust, seal edges and vent with 9 angled slashes. Brush with egg white and sugar wash. Bake 350° for about 45 minutes til golden. Coolthe Apple Jack and cut in diamond shapes.
Note: you can substitute 4 cans of pie filling for the apples.