Preheat and prep. Heat your oven to 350°F (175°C). Place a rack in the lower third. Set your chilled pie crust in a 9-inch pie plate, crimp the edges, and keep it in the fridge while you make the filling.

Toast the pecans. Spread pecan halves on a baking sheet and toast for 7–9 minutes, until fragrant. Let them cool slightly. Roughly chop about two-thirds of them, leaving the rest whole for visual appeal.

Mix the wet ingredients. In a large bowl, whisk the eggs until well combined. Add brown sugar, maple syrup, corn syrup, melted butter, bourbon, vanilla, and salt. Whisk until smooth. If using, sprinkle in the flour and cinnamon and whisk again.

Add the pecans. Stir in the chopped pecans. Reserve the whole pecans for arranging on top, or just mix them all in if you prefer a more rustic look.

Fill the crust. Pour the filling into the chilled crust. If using whole pecans on top, arrange them in circles for a neat finish.

Shield the edges. To prevent over-browning, cover the crust edges with a pie shield or strips of foil.

Bake. Bake for 45–55 minutes, until the edges are set and the center jiggles slightly like gelatin. If the top is browning too fast, tent loosely with foil for the last 10 minutes.

Cool and set. Let the pie cool completely on a rack, at least 3–4 hours. The filling continues to set as it cools. For clean slices, chill for 1 hour before cutting.

Finish. Sprinkle a tiny pinch of flaky sea salt over the top before serving to brighten the sweetness, if you like.