To prepare a white chocolate chip buttermilk pie, you will first need to prepare your pie crust. Preheat the oven to 375 degrees F (190 degrees C) and grease the pie shell with butter. Place the sugar, butter, eggs, vanilla, and salt into the mixing bowl. Beat the mixture with an electric mixer until it's light and fluffy, about 5 minutes. Add the flour and mix until just combined. Gradually add the milk, beating well after each addition. Fold in the chocolate chips. Bake for 45 to 50 minutes, or until the filling is bubbly and golden brown. Remove from oven and let cool before cutting into squares.