Perfecting the pie that plucks at American heartstrings is simple when an assortment of apples is used. Try mixing some Macoun with Granny Smith, Cortland, Jonagold, and Empire. Most important, buy the fruits fresh and firm.
On a lightly floured work surface, roll out one pate brisee disc into a 13-inch round about 1/8 inch thick. Fit dough into a 9-inch pie plate. With a sharp paring knife, trim dough flush with the rim. Freeze again until firm, at least 30 minutes.
Roll out remaining 2 discs of pate brisee to about 1/8 inch thick. Place on a parchment-lined baking sheet, and freeze until firm, at least 30 minutes. Remove from freezer; using a 2 1/4-inch leaf-shaped cutter, cut out about 65 leaves and place them in a single layer on baking sheet. Place in refrigerator until firm.
Preheat oven to 400 degrees. In a small bowl, whisk together egg yolk and heavy cream; set aside. In a large bowl, toss the apples with the lemon juice, granulated sugar, flour, cinnamon, nutmeg, and salt. Remove pie shell from freezer, and fill with apple mixture. Dot with butter.
Remove leaves from refrigerator, and score with a paring knife to make veins. Lightly brush the edge of the pie shell with water. Brush the bottom of each leaf with water; beginning with the outside edge, arrange leaves in a slightly overlapping ring. Repeat to form another ring slightly overlapping the first. Continue until only a small circle of filling is left uncovered in the center.
Carefully brush the top of the leaves and pie edge with the reserved egg wash, and sprinkle generously with sanding sugar. Freeze or refrigerate until firm, at least 30 minutes.
Place pie plate on a baking sheet, and bake until crust just begins to brown, about 20 minutes. Reduce oven temperature to 350 degrees and continue baking until crust is golden brown and juices are bubbling, 35 to 45 minutes. If the crust begins to get too dark, drape a piece of aluminum foil over the top. Transfer to a wire rack to cool.
For the flakiest and most evenly browned crust, use a glass pie dish. Freezing the top layer of pie dough before cutting out the leaves will help produce very smooth edges.