Preheat the oven to 425 degrees F (220 degrees C). Press the pie crust into the bottom and up the sides of a 9 inch deep dish pie plate.

In a medium bowl, beat the butter, sugar, and eggs until light and fluffy. Stir in the cornmeal, vinegar, and maple extract until well blended. Fold in pecans so they are evenly distributed. Pour into the unbaked pie crust.

Bake for 10 minutes in the preheated oven, then reduce the heat to 350 degrees F (175 degrees C). Bake for 30 additional minutes, or until the top of the pie is golden brown, and the filling is set. When removing the pie from the oven, give it a gentle shake. If there is no movement, the pie is set. The pie will thicken and shrink slightly upon cooling.