Preheat the oven to 350°F.
Fit the pie dough into a 9-inch pie dish. Crimp the edges if desired. Place a piece of foil over the pie dough and then add pie weights or dried beans. Blind bake the dough for 20 minutes. Remove from oven and carefully remove the foil with weights/beans. Let cool completely. Leave the oven on.
In a large bowl, mix together the flour, cornmeal, sugar, vanilla, sour cream, buttermilk, lemon juice, and lemon zest. Stir in the melted butter and lightly beaten eggs until fully incorporated. The batter should be smooth, but a few small lumps are okay.
Pour into the unbaked pie shell.
Bake the pie on the center rack for 50 to 55 minutes, or until the center is set, and an inserted toothpick comes out clean.
Remove the pie from the oven and allow it to cool completely.
If desired, top with fresh berries and sprinkle confectioners' sugar over the top.