Heat the oven to 350°F (175°C) with a rack in the lower third. Whisk the maple syrup, brown sugar, eggs, melted butter, vanilla, and salt until completely smooth.

Place the pie crust on a baking sheet and scatter the pecans evenly in the bottom. Pour the filling slowly over the nuts, then let it settle so the pecans float to the top.

Bake for 50 to 55 minutes, until the edges puff and the center wobbles slightly when you shake the pan. Cover the crust edges with foil after 30 minutes if they brown too fast.

Cool the pie on a wire rack for at least 2 hours, then slice and serve at room temperature.