Preheat oven to 350 degrees F.
In a large bowl, add the sugar, buttermilk, eggs, butter, and vanilla. Whisk until well combined.
Add the flour and salt. Whisk until no dry flour remains.
Add the blueberries. Gently stir until well incorporated.
Place the pie crust in a 9-inch pie plate. Pour the pie filling into the pie crust.
Bake for 50 minutes.
Cool at room temperature for 1 hour. Then, refrigerate for at least 2 hours before serving.
