Prepare the Pie Crust: Roll out the chilled pie dough on a lightly floured surface to a 12-inch circle. Gently transfer it to a 9-inch pie plate, ensuring the edges hang over slightly. Trim excess dough, then crimp the edges for a decorative touch. Chill the crust in the refrigerator while you prepare the filling.

Make the Filling: In a large mixing bowl, whisk together the pumpkin puree, evaporated milk, maple syrup, eggs, pumpkin pie spice, and vanilla extract until smooth and fully combined. Pour the mixture into the prepared crust.

Bake: Preheat oven to 425°F (220°C). Bake for 15 minutes, then reduce to 350°F (175°C) and continue baking for about 50 minutes. Cover edges with foil if they brown too quickly.

Prepare the Streusel: In a medium bowl, combine chopped pecans, brown sugar, flour, and sea salt. Add cold, cubed butter and blend until the mixture resembles coarse crumbs.

Add Topping: In the last 20 minutes of baking, evenly sprinkle the prepared pecan streusel over the filling. Bake until filling is firm but slightly jiggly in the middle, and the topping is golden brown, about 20 minutes more.

Cool & Serve: Remove the pie from the oven and let it cool on a wire rack for about 3-4 hours. Refrigerate for at least an hour before serving. Slice and serve chilled or at room temperature.