In a food processor, combine all-purpose flour, granulated sugar, and salt. Pulse until mixed, then add cold butter in chunks until the mixture resembles coarse crumbs. In a separate bowl, whisk the egg, white vinegar, and ice-cold water together. Gradually add this wet mixture to the flour mix until a dough forms. Flatten it into a disk, wrap in plastic, and refrigerate for 30 minutes to chill.

Preheat your oven to 375°F (190°C). Roll the chilled dough on a lightly floured surface into a 12-inch circle. Transfer it to a pie plate, trimming any excess dough hanging over the edges. Line the crust with parchment paper and fill with pie weights or baking beans. Bake for 15 minutes until the edges are lightly golden. Remove from the oven to cool and lower the temperature to 350°F (175°C).

In a large mixing bowl, whisk together canned pumpkin, sour cream, eggs, bourbon, and vanilla extract until smooth. Add spices like cinnamon, ginger, nutmeg, cardamom, and allspice, along with salt and maple syrup. Make sure the mixture is well combined, adjusting the spices and sweetness to your taste. If the filling looks too thick, incorporate a splash of cream to achieve a silky consistency.

Pour the luscious filling into the pre-baked pie crust, using a spatula to spread it evenly. Tap the pie gently on the counter to help release any trapped air bubbles. This step is crucial for an even bake and a smooth texture in your Bourbon Brûlée Pumpkin Pie.

Place the assembled pie in the oven and bake at 350°F (175°C) for approximately 45 minutes. The filling will appear set but should still jiggle slightly in the center. This indicates that it's perfectly creamy inside.

Allow the pie to cool completely at room temperature. Once cooled, evenly sprinkle a thin layer of granulated sugar over the top. Using a kitchen torch, carefully caramelize the sugar until it forms a golden, crunchy layer.