In the bowl of a food processor, pulse the All-Purpose Flour (2 1/2 cup), Granulated Sugar (2 tablespoon) and Kosher Salt (1/2 teaspoon) together. Cut the Unsalted Butter (1 cup) into small pieces, then add to the food processor. Pulse at 1-second intervals until butter is the size of peas. Add the Water (1/2 cup) and pulse again about 10 times until the mixture is crumbly but holds together when pinched.
Lay two clean tea towels on a work surface. Dump half of the crumbly dough mixture into the center of each. Grab the four corners of the towel together and twist to create a beggar's purse, pressing the dough into a disk. Unwrap the towel and use your hands to pack and pat the disk together. Wrap the rounds in plastic wrap, tuck in a ziplock bag, and store in the fridge for 3 days or freezer for 3 months.
If baking one immediately, lightly flour a work surface, roll out into a circle an inch or two larger than your pie plate, transfer to pie plate, trim over hanging dough, then crimp dough as desired. Chill in fridge while you prepare the filling.
To blind bake the pie dough, preheat the oven to 375 degrees F (190 degrees C). Prick the pie dough a few times with a fork. Line the pie dough with aluminum foil and fill halfway with beans, rice, or pie weights. Bake until the dough is set and starting to get lightly golden brown, about 15-20 minutes.
Lift out the foil with the weights and bake until the dough is well-browned, about 5-8 minutes more. Turn the oven down to 350 degrees F (180 degrees C).
To make the filling, in a large bowl, whisk together the Dark Brown Sugar (1 cup), Maple Syrup (1/2 cup), Large Egg (3), Butter (4 tablespoon), Bourbon (3 tablespoon), Vanilla Extract (1 teaspoon), and Salt (1/4 teaspoon). Stir in the Roasted Pecans (2 cup).
Pour the filling into the pre-baked tart shell and bake until the center of the pie seems just about set. It should still jiggle a little. Begin checking it at the 40 minute mark, but it may take 45-50 minutes to reach that point of doneness.
Remove it from the oven and let cool on a wire rack. To make the salted whipped cream: Whip Heavy Cream (1 cup) in the bowl of a stand mixer until soft peaks begin to form. Add Powdered Confectioners Sugar (1/4 cup). Add Sea Salt Flakes (1 pinch) and Vanilla Extract (to taste) and beat to combine until the peaks begin getting firmer.
Serve at room temperature.