Preheat oven to 350 F. Roll out pie crust and fit into a round 9-inch pie plate.
In a large bowl, whisk together sugar, cocoa powder, salt, cornmeal and flour. Add in eggs, milk, melted butter, vinegar and vanilla extract. Whisk until smooth.
Pour mixture into the prepared pie crust. Bake for 50-55 minutes. Let cool completely.