In a large liquid measuring cup, whisk together the water and vinegar. Add the ice and whisk. Refrigerate while you prep the rest of the ingredients.
Cut the butter into 1-inch cubes and place them in a small bowl. Freeze while you prep the rest of the ingredients.
In the bowl of a stand mixer fitted with the paddle attachment, combine the flour, C&H® Granulated Sugar, and salt. Beat on low until just combined, about 15 seconds. Add the butter all at once and beat on low until the mixture has the texture of coarse meal, with pea-sized pieces of butter throughout, about 3 minutes.
Remove the ice water mixture from the refrigerator. With the mixer on low, add 6 tablespoons of liquid from the ice water mixture. Beat on low for 2 to 3 minutes, or until the dough clumps around the paddle and/or the sides of the bowl. If the dough seems too dry, add more liquid from the ice water mixture 1 teaspoon at a time.
Tip the dough out onto a lightly floured counter with a rubber spatula. Quickly knead the dough into a rough ball. Wrap tightly in plastic wrap and flatten into a small disc. Refrigerate for at least 1 hour.
Roll the dough into a 10-inch circle. Transfer the dough onto your pie pan. Crimp the edge. Cover loosely with plastic wrap and freeze for at least 4 hours, preferably overnight.
Position a rack in the center of the oven and preheat the oven to 350°F. Line a half sheet pan with parchment paper.
Place the frozen crust, still in its plate, in the center of the pan. Cover the crust with foil, making sure the crimped edges are completely covered and that there are no gaps between the foil and the crust. Fill with pie weights and spread them out so they are more concentrated around the edges of the crust.
Bake for 35 minutes. While the crust is in the oven, make the egg wash: In a small bowl, whisk together the egg white and water.
Remove the sheet pan from the oven, keeping the oven on. Carefully lift out the pie weights and foil. Use a pastry brush to coat the bottom and sides of the pie crust (but not the crimped border) with a thin layer of egg wash. Bake, uncovered, for an additional 5 minutes. Set aside on a wire rack to cool completely.
Place the dark chocolate in a small heatproof bowl. Bring the heavy cream just to a heavy boil over medium heat in a small, heavy-bottomed saucepan. Remove from heat and immediately pour over the chocolate, then place a heatproof plate over the bowl to create a makeshift lid. Let sit, undisturbed, for 5 minutes.
Remove the plate. Whisk slowly but steadily until the ganache is thick, smooth, and shiny. Scrape the ganache into the cooled pie shell and spread evenly over its bottom and sides with an offset spatula. Place the shell in the freezer to set the ganache while making the filling.
Position a rack in the center of the oven and preheat the oven to 375°F. Line a half sheet pan with parchment paper.
In a large bowl, mix together the C&H® Light Brown Sugar, flour, and salt. Mix in the milk until combined. Mix in the eggs, one by one, adding the next egg only when the previous egg has been incorporated. Mix in the vinegar, vanilla, butter, and diced pecans.
Place the ganache-coated pie crust on a parchment-lined half sheet pan and pour in the filling. Scatter the pecan halves on top.
Bake for 50 to 55 minutes, or until the edges are set and the center of the pie just slightly jiggles. Cool on a wire rack.
Serve slightly warm or at room temperature. The pie can be kept at room temperature, under a cake dome or a large bowl turned upside down, for 1 day. After that, cover tightly in plastic wrap and refrigerate for 2 more days.
The recipe can also be made with store-bought, deep-dish frozen pie crust. Follow the recipe instructions to pre bake the pie but reduce the initial Bake Time from 35 minutes to 30 minutes.
Check the assembled pecan pie during its Bake Time at 40 minutes. If the crust is browning too quickly, tent the pie with a sheet of aluminum foil.