Combine flour, sugar, and salt in a large bowl. Cut in chilled butter until pea-sized pieces form.
Add 1/4 cup ice water and mix until dough starts to come together, adding more water if necessary.
Form dough into a disc, wrap in plastic wrap, smooth edges, and refrigerate for 1 hour or up to 2 days.
Roll dough on a floured surface into a 12-13 inch circle and place in a lightly sprayed 9-inch pie plate.
Trim and crimp edges, then refrigerate crust for 20 minutes while preparing filling.
Preheat oven to 350°F with a rack in the center to lower third.
Melt butter in a saucepan over medium heat. Add brown sugar and maple syrup, whisk until smooth and simmer gently.
Remove from heat and cool mixture in a bowl for 15 minutes.
Whisk in eggs, salt, and extract until fully combined.
Sprinkle chopped, toasted pecans evenly in the bottom of the pie crust.
Pour syrup mixture over pecans, rearranging if needed.
Spray foil lightly with non-stick spray and cover pie with foil.
Bake for 30 minutes covered, then remove foil and bake another 15-25 minutes until edges are set and center is slightly jiggly.
Sprinkle flaky finishing salt on top and cool pie completely on a wire rack before serving.
Serve at room temperature with vanilla ice cream if desired.