Reduce the oven temperature to 350°F.
In a large bowl, combine butter, sugar, and vanilla. Whisk together until combined.
Add the eggs, one at a time, making sure they are fully incorporated after each addition.
Add cornmeal, flour, buttermilk, and vinegar. Mix to combine.
Pour the filling into the crust and bake for 50-55 minutes, or until the pie is completely set.
Let the pie cool at room temperature for 30-45 minutes before transferring to the refrigerator to cool completely (about 2 hours).
Dust with confectioners' sugar and garnish with whipped topping. Enjoy!