How to Make It
On a floured work surface, roll out the larger disk of dough to a 13-inch round. Fold the round in quarters and transfer to a 9-inch glass pie dish; unfold the pastry and gently press it into the pie plate. Lightly brush the bottom of the dough with some of the egg white. Roll out the smaller disk of pie dough to a 12-inch round. Fold the round in quarters, transfer it to a wax paper–lined baking sheet and unfold. Freeze the pie shell and the 12-inch round of dough for 15 minutes.
Preheat the oven to 400°. In a bowl, toss the apples with the 1/2 cup of sugar and the apricots, zest, cinnamon and 1 tablespoon of flour.
Scrape the apples into the pie shell and dot with the butter. Brush the edge with some of the egg white and top with the second round of dough. Press the edges together and, using scissors, trim the overhang to 1/2 inch. Fold the edge under itself and crimp decoratively. Brush the pie with the milk and sprinkle with sugar. Cut slashes in the top of the pie to vent steam.
Bake the pie in the lower third of the oven for 1 hour, until the crust is deep golden and the filling is bubbling through the vents; tent with foil during the last 20 minutes of baking. Cool completely before serving.