Nannies Buttermilk Pie

Ingredients

• 1 3/4 C. sugar
• 1 stick unsalted butter (1/2 C.) room temp.
• 3 large eggs
• 1/4 tsp. vanilla extract
• pinch of salt
• 3 T. all purpose flour
• 1 C. buttermilk
• 1 9" pie shell, unbaked