01 -
Set oven temperature to 350°F (177°C).
02 -
In a large bowl, stir together granulated sugar and all-purpose flour until evenly blended.
03 -
Add buttermilk, melted salted butter, eggs, fresh lemon juice, and vanilla extract to the dry mixture; whisk until smooth and fully incorporated.
04 -
Pour the prepared filling into the 9-inch deep dish pie crust placed on a sheet tray to catch any drips.
05 -
Bake for 55 to 70 minutes until the top is golden brown and the filling is set but slightly jiggly in the center. If browning too quickly, cover loosely with aluminum foil.
06 -
Allow to cool at room temperature for at least 3 hours before serving, or refrigerate and serve chilled as preferred.