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