Preheat the oven to 400 F (204 C).
In a mixing bowl, add the sugar, salt and butter. Using a flat beater and on Medium Low speed, cream together the ingredients until light and fluffy, approximately 2 minutes. Add the egg and vanilla extract while continuously beating until incorporated. On Low speed, gradually add the flour. Beat until well incorporated, (dry flour is no longer visible), approximately 2-3 minutes. Scrape the dough off the flat beater and down the sides of the bowl. Mix together for another 30 seconds.