How to Make It
In a small bowl, combine the water and vodka and chill the mixture in the freezer until very cold. In a food processor, pulse both flours with the sugar and salt. Add the butter and pulse in 1-second bursts until the mixture resembles coarse meal. Drizzle the vodka water on top. Pulse in 1-second bursts until the dough just comes together. Turn the dough out onto a work surface, gather up any crumbs and pat the dough into a disk. Wrap in plastic and let rest at room temperature for 30 minutes.
On a floured work surface, roll out the dough to an 11-inch round, a scant 1/4 inch thick. Ease the dough into a 9-inch glass or ceramic pie plate. Trim the overhanging dough to 1 inch, fold it under itself and crimp decoratively. Freeze the crust until firm, about 15 minutes.
Preheat the oven to 350°. Line the crust with parchment paper and fill with pie weights or dried beans. Bake the crust in the lower third of the oven for about 25 minutes, until barely set. Remove the parchment paper and pie weights. Cover the edge of the crust with strips of foil and bake for about 10 minutes longer, until the crust is lightly browned. Let cool on a rack. Leave the foil strips on the crust rim.
In a large bowl, whisk the condensed milk with the sugar, salt and vanilla bean seeds. Add the eggs and egg yolks, then whisk in the butter and cornmeal. Stir in the crème fraîche until combined.
Set the pie plate on a baking sheet. Pour in the custard and bake for 35 to 40 minutes, until the custard is set around the edge but the center is slightly jiggly. Let the pie cool completely, then refrigerate for at least 3 hours or overnight before serving.