Preheat oven to 350.
Place top crust on floured surface.
Place inverted pie plate on crust and cut cirle to size.
Discard excess dough.
Cut into strips and basketweave into lattice top. Set aside.
Place the bottom crust in pie pan.
Brush bottom crust with egg whites and dock with fork.
Fill with apples, mounded slightly. Set aside.
Melt the butter in a pan.
Add in flour stir to form a roux. Cook for 2-3 minutes.
Stir in water, sugar, cinnamon and brown sugar.
Bring to a boil, reduce heat and let simmer for 4-5 minutes.
Add vanilla and cornstarch and mix.
Evenly pour/spread 2/3 of this mixture over the apples.
Cover with prepared lattice pie crust.
Brush lattice crust with egg whites.
Evenly pour/spread remaining sugar mixture over the crust
Bake 60-70 minutes, until apples are soft.