If you're going to make pecan pie once a year, this is the way to do it. A touch of bacon fat in the dough not only yields blue-ribbon-flaky crust, but its smokiness also balances out the sweet toffee filling.
Crust part 1: Place flour, sugar, salt, and butter in the bowl of a stand mixer fitted with a paddle attachment. Mix on low for 10 seconds, then add bacon fat and continue mixing until the dough resembles small peas. Add the egg beaten with ice water just to incorporate, 10 seconds more. Turn off mixer and finish dough by hand until it holds together when squeezed with fingers (if needed, add more ice water, ¼ teaspoon at a time). Do not over-moisten. Turn out onto a clean work surface and bring together to a round disc. Wrap dough in plastic and refrigerate for 2 hours and up to overnight.
Filling: Preheat oven to 375 degrees F. In a mixing bowl, whisk the eggs, then whisk in both sugars, vanilla, salt, dark corn syrup, and butter. Set aside.
Crust, part 2: Spray a sheet of parchment paper with non-stick spray and place spray-side down on a flat surface (to keep it from sticking, of course!). Dust with flour and roll out chilled dough to a 15-inch round (¼-inch thick). If the dough sticks to the parchment, dust the dough with flour, place another sheet on top and flip over so the top sheet is now on the bottom. The dough will release easily from the parchment.
Spray pie tin with non-stick spray, gently fold the pie crust in half (for easy transfer), and fit into the tin. There should be about a 2-inch overhang. Tuck the overhang under so the dough fits the pan, then create a lip to seal the edges. For a crimped edge, use a spoon to indent the dough to form a U-shape around the crust, trimming excess dough as you go along. Chill crust for at least 10 minutes to relax.
Assembly: Place toasted pecans in bottom of chilled pie tin. Pour filling on top and tap a few times on the counter to settle filling and pecans. Place on a sheet pan (to catch drips) and put into the oven. Immediately turn temperature down to 350 F and bake 40 minutes. Reduce heat to 300 degrees F and bake 20 minutes more. If pecans begin to darken, place foil over top and continue cooking.
When crust is golden and filling is puffed and set, remove pie from the oven to cool. Serve slightly warm or room temperature, with a dusting of confectioners' sugar.