Preheat oven to 425 degrees F. Unroll pie crust and place in pie plate, crimp or score edges with a fork then cover with parchment paper and fill with pie weights or dried beans.
Place in oven for about 5 minutes then remove beans and parchment. Bake for 2-3 more minutes. Remove from oven and let cool slightly.
Meanwhile, make your filling in a large bowl by whisking together the sugar, flour, cornmeal, and salt.
Add in melted butter, milk, vinegar, and vanilla. Whisk until combined. Lastly, add in the eggs and whisk until just combined.
Pour filling into your prepared crust and bake for about 1 hour until dark brown on top and center is set.
Let cool completely then sprinkle with powdered sugar if desired.
Notes
Cover edges of pie crust with tin foil or pie shields to prevent burning after they start to brown.