Prepare the Crust:

1. In a food processor, blend flour, sugar, and salt.
2. Whisk the egg, vinegar, and water in a small bowl.
3. Add butter pieces to the processor and pulse until coarse crumbs form.
4. Slowly add the egg mixture while pulsing until dough begins to form.
5. Wrap dough in plastic wrap and refrigerate for 30 minutes.
6. Preheat oven to 375°F.
7. Roll out chilled dough to a 12-inch circle and place in a 9-inch pie plate. Trim and decorate edges as desired.
8. Cover crust with parchment paper and add pie weights or beans. Bake for 15 minutes, then remove weights, brush with egg white, and reduce oven temperature to 350°F.

Prepare the Filling:

1. In a large bowl, whisk together eggs, pumpkin purée, sour cream, vanilla, and spices.
2. Heat maple syrup in a small saucepan until it simmers. Cook for 2-3 minutes, then remove from heat and whisk in heavy cream.
3. Gradually add the maple mixture to the pumpkin mixture, stirring until smooth.
4. Pour filling into the prepared crust.

Bake the Pie:

1. Bake for 55-60 minutes, or until the center is slightly jiggly but set.
2. Let pie cool completely, then refrigerate overnight for the best texture.

Brûlée Topping:

1. Before serving, evenly sprinkle 3 tablespoons of sugar over the top of the pie.
2. Use a kitchen torch to caramelize the sugar until golden and crisp.
3. Slice and serve for an unforgettable dessert experience!