In a food processor, combine flour, sugar, and salt, pulsing until mixed. Add cold, cubed butter and pulse until the mixture resembles coarse crumbs. In a separate bowl, whisk together the egg, vinegar, and ice-cold water. Drizzle this mixture into the flour mixture, pulsing until just combined. Chill the dough for 30 minutes, then roll it into a 12-inch round, fit it into a pie plate, and crimp the edges gently.

Preheat the oven to 375°F. Line the crust with parchment paper and fill it with pie weights or dried beans. Blind bake for 15 minutes until lightly golden. Remove the weights and parchment, then brush the crust with egg white to seal. Return to the oven for an additional 5 minutes.

In a large mixing bowl, whisk together the large eggs, canned pumpkin, sour cream, vanilla extract, warm bourbon, and the delightful blend of spices. In a small saucepan, gently heat maple syrup until bubbling, then gradually whisk in heavy cream until fully combined. Pour this creamy filling into the prepared crust, smoothing the top for an even layer.

Reduce the oven temperature to 350°F. Carefully place the filled pie into the oven and bake for 55-60 minutes. The filling should be set with just a slight jiggle in the center when done.

Once baked, remove the pie from the oven and allow it to cool at room temperature for about an hour. Then, refrigerate it overnight to let the flavors meld beautifully.

Just before serving, sprinkle an even layer of granulated sugar over the chilled pie. Use a culinary torch to caramelize the sugar until it forms a crisp, golden crust.