Makes enough for a sheet pan 10.5" x 15.5" x 1" high.
Combine ingredients, cook until thick, then cool.
Combine in large bowl; sugar, flour, baking soda, baking powder, and salt.
Cut in shortening until it is in little pieces
Add eggs, milk and vanilla and blend well
Divide dough in half.
Roll out one half between sheets of wax paper and line bottom of sheet pan.
Add filling.
Roll out remaining half of dough between waxed paper and carefully place on top of filling.
Seal edges and bake at 350 degrees F for 30 minutes.
Servings 12