Adjust an oven rack to the middle position and heat the oven to 325 degrees. Grease and flour a 9 by 5 inch loaf pan.

In a standing mixer fitted with the flat beater, beat the butter and salt at medium high speed until shiny, smooth and creamy, 2 to 3 minutes, scraping the bottom and sides of the bowl once with a rubber spatula. Reduce the speed to medium with the mixer running, gradually pour in the sugar (this should take about 60 seconds). Once all the sugar is added, increase the speed to medium-high and beat until the mixture is fluffy and almost white in color, 5 to 8 minutes, scraping the bottom and sides of the bowl once. With the mixer running at medium speed, gradually add the egg mixture in a slow, steady stream; this should take 60 to 90 seconds. Scrape the bottom and sides of the bowl; beat the mixture at medium-high speed until light and fluffy, 3 to 4 minutes (the mixture may look slightly broken.) Remove the bowl from the mixer; scrape the bottom and sides.

In 3 additions, sift the flour over the butter/egg mixture; after each addition, fold gently with a rubber spatula until combined. Scrape along the bottom of the bowl to ensure that the batter is homogeneous.

Transfer the batter to the prepared loaf pan and smooth the surface with a rubber spatula. Bake until golden brown and a wooden skewer inserted into the center of the cake comes out clean, about 70 to 80 minutes. Cool the cake in the pan on a wire rack for 15 minutes; invert the cake onto a wire rack, then turn the cake right side up. Cool the cake on a wire rack to room temperature, about 2 hours.

Slice and serve. This pound cake also freezes well.