Preheat oven to 325 degrees.
Scatter blueberries evenly in prepared pie crust.
In a large bowl, whisk together eggs, buttermilk, melted butter, lemon juice, and vanilla extract.
In a medium bowl, whisk together sugar, flour, and salt to get all clumps out.
Add flour mixture to egg mixture and stir until smooth. Pour mixture over blueberries
Bake for 50-60 minutes or until golden brown and it just has a little jiggle in the center when you shake it.
Cool pie on the counter for 30 minutes and then refrigerate for at least 2 hours before serving.
