I prefer this with all Granny Smith apples. The original recipe, from Southern Living, calls for half Grannies and half Braeburns, a sweeter apple. Just depends on your own preference. Everything is a cast iron skillet is good!
Peel apples, and cut into 1/2" thick wedges. Toss apples with cinnamon and 3/4 cup granulated sugar.
Melt butter in a 10" cast-iron skillet over medium heat; add brown sugar, and cook, stirring constantly, 1-2 minutes or until sugar is dissolved. Remove from heat, and place one piecrust in skillet over brown sugar mixture. Spoon apple mixture over piecrust, and top with remaining piecrust.
Whisk egg white until foamy. Brush top of pie with eggwhite; sprinkle to 2 tablespoons sugar. Cut 4-5 slits in top for steam to escape.
Bake for 60-70 minutes or until golden brown and bubbly, shielding with aluminum foil during last 10 minutes to prevent over browning, if necessary.
Cool on a wire rack 30 minutes before serving. Serve warm with ice cream.