You don't need an actual stencil to create the striking cinnamon-sugar top crust for this apple pie -- an artful arrangement of popsicle sticks does the trick. For the decorating technique, see our step-by-step photos.
In a large, heavy-bottomed saucepan, melt butter over medium heat. Stir in apples, lemon juice, 1/2 cup sugar, 1/2 teaspoon cinnamon, and salt; cover and cook until apples have softened but are not falling apart, about 8 minutes. Add flour and cook, uncovered, until juices have thickened, about 2 minutes. Transfer to a 9-by-13-inch baking dish; let cool completely.
On a lightly floured piece of parchment, roll out 1 disk of dough into a 13-inch round, about 1/8 inch thick. Fit into a 9-inch pie dish. Refrigerate until firm, at least 30 minutes. Meanwhile, roll out remaining disk of dough on a lightly floured piece of parchment to a 13-inch round, about 1/8 inch thick. Transfer on parchment to a baking sheet and, using a small round cutter or paring knife, cut a 1-inch hole in center. Brush top dough with egg white and refrigerate until firm, about 30 minutes.
Place apple mixture in prepared pie dish; spread in an even layer. Lightly brush rim of bottom dough with water. In a small bowl, combine remaining 1 tablespoon sugar and 1/2 teaspoon cinnamon.
Using a 9-inch cake pan or plate, trace a circle on a piece of parchment; cut out inside of circle and reserve for another use. Center resulting hole over top dough. Place 4 ice-pop sticks around center hole, at 90-degree angles. Starting at center and working outward, place sticks 1/2 inch apart, gently pressing onto dough to adhere, to create an arrow pattern toward center of dough. (If dough gets too soft, refrigerate for a few minutes until firm.) Using a small sieve, sprinkle with cinnamon sugar. Brush excess sugar off sticks; carefully remove sticks, then parchment. Center stenciled dough over filling. Trim dough, leaving a 1-inch overhang. Tuck overhang under edge of bottom dough; gently pinch to seal. Crimp as desired. Refrigerate until firm, about 30 minutes.
Preheat oven to 400 degrees with a rack in lower third and a foil-lined baking sheet below. Place dish directly on rack; bake until crust is just beginning to brown, about 20 minutes. Reduce oven temperature to 375 degrees; bake until crust is golden brown and juices are bubbling in center, 1 hour to 1 hour, 10 minutes. (If crust is browning too quickly, tent with foil.) Transfer to a wire rack; let cool completely, at least 6 hours.