Heat oven to 350 F. Grease 9-by-13 pan.
To diced apples add apple butter, 1 tsp. vanilla and brown sugar. Mix until apples are evenly coated.
Slowly stretch out one crust to cover pan’s bottom. Cut some edges off, if necessary. Spread apple filling evenly.
With rolling pin, roll second crust to make it same size as pan. Place on top of filling and tuck down edges to cover.
Topping: Whisk egg white until foamy and brush over crust. Combine sugar and cinnamon, and sprinkle on top.Bake 50-60 minutes until crust is golden brown. Remove from oven and cool slightly before cutting.
Glaze: In small bowl, whisk until smooth powdered sugar, milk and remaining vanilla. Drizzle over cooled bars and serve.