Preheat oven to 425 °F
Roll out and place bottom crust into a 9-inch pie dish. Set aside.
Place sliced apples in a bowl and set aside.
In a saucepan over medium heat, melt butter. Stir in flour and cook for 1 minute.
Add white sugar, brown sugar, water, salt, and apple pie spice. Bring to a gentle boil and simmer for 2-3 minutes until smooth and thickened. Pour sauce over apples and gently combine. Place apple mixture in crust lined pie dish.
Cover with top crust (lattice or full). Seal edges and cut slits if using full crust.
Brush crust with egg wash.
Bake 15 minutes at 425 °F. Then reduce heat to 350 °F and bake for another 35 to 45 minutes until golden and bubbling.
Cool for at least 1 hour before slicing to let the filling set.