How to Make It
Preheat the oven to 350°. Fit one of the piecrusts into a 9-inch pie plate and sprinkle with the cornmeal. Refrigerate until ready to use.
In a large bowl, toss the apples with both sugars, the lemon juice, cinnamon and salt. Let stand for 30 minutes.
Scrape the apples and their juices into the pie shell. Top with the second crust and press the edges together to seal. Trim the crust to the edge of the plate, then crimp decoratively. Place the pie on a baking sheet and brush the top with the egg wash. Cut 6 slits in the top and bake for about 45 minutes, until the crust is golden and the apples are tender. Transfer to a rack and let cool to room temperature before serving.