In a food processor, pulse together 1 ¼ cups of all-purpose flour, 2 tablespoons of granulated sugar, and a pinch of salt until combined. Add in 1 large egg (lightly beaten), 1 tablespoon of white vinegar, and 3-4 tablespoons of ice-cold water, then blend until the mixture resembles coarse crumbs. Wrap this dough in plastic wrap and refrigerate for about 30 minutes, allowing it to firm up.

Preheat your oven to 375°F (190°C). On a lightly floured surface, roll out the chilled dough to fit your pie plate, then place it inside. Use parchment paper and add pie weights, then blind bake for 15 minutes. Afterward, remove the weights, brush the crust with a lightly beaten egg white, decrease the oven temperature to 350°F (175°C), and bake for an additional 5 minutes until golden and set.

In a mixing bowl, whisk together 3 large eggs, 1 can (15 oz) of 100% pure pumpkin, and ½ cup of sour cream until smooth. Stir in ¼ cup of bourbon, a teaspoon each of vanilla extract, ground cinnamon, and nutmeg, followed by ½ cup of maple syrup. Heat ½ cup of heavy cream in a small saucepan until warm, then whisk it into the pumpkin mixture, ensuring a creamy, well-blended filling.

Pour the pumpkin filling into the pre-baked crust. Bake in the preheated oven at 350°F (175°C) for 55-60 minutes, watching closely until the edge is set while the center remains slightly jiggly. Remove the pie from the oven and allow it to cool completely at room temperature for at least 2 hours, which helps to firm the filling.

Once the pie is completely cooled, refrigerate it overnight to allow the flavors to meld. Just before serving, sprinkle a generous layer of granulated sugar evenly over the top of the pie. Using a kitchen torch, carefully caramelize the sugar until golden and bubbly, creating that delicious brûlée topping that adds a perfect crunch to your Bourbon Brûlée Pumpkin Pie.