Add the sugar, cornmeal, flour, and salt to a large bowl and whisk to combine. Add the butter, milk, vinegar, and vanilla, and whisk to combine. Whisk in the eggs.
Pour the mixture into your pie crust.
Bake until the pie is golden and edges are set but the center has some wiggle, about 60 to 75 minutes. Start checking the pie for doneness around the 45 minute mark and every 10 or 15 minutes after. If the crust starts to get too dark before the pie is done, cover it with foil (usually around the 45-minute mark).
Let the pie cool to room temperature (about 2 hours) before slicing and serving.
To serve, dust the top with powdered sugar.
Notes
The key ingredient in chess pie is cornmeal, I would not suggest leaving it out. The cornmeal thickens the custard filling. The vinegar called for in the ingredients helps balance the sweetness. Instead of distilled white vinegar, you can use 1 1/2 tablespoons of fresh lemon juice.
For convenience, we used a frozen crust. You can also use a store-bought refrigerated pie crust that you roll out and place in a standard 9-inch pie plate, or you can make your own homemade pie crust. However, note that your bake time might vary if you’re using a different crust. Bake time can also vary depending on the material your pie plate is made of.
If you’re using a store-bought frozen pie crust, thaw it in the fridge. When you use it, it should be chilled but not frozen for the best results.