Heat oven to 325F. Lightly grease a 9x5x3 bread pan. Beat butter in a bowl until smooth, about 30 seconds. With mixer on low speed, gradually add sugar. Increase speed to high and beat until light and fluffy.

With mixer still on high, add eggs one at a time, beating well after each addition. Add vanilla and salt and beat until very pale in color and increased in volume.

With a rubber spatula, mix in flour, about a third of a cup at a time, until smooth. Scrape batter into prepared pan and bake for 1 hour and 15 minutes or until a pick inserted in the middle comes out clean.

Cool cake in pan for 15 minutes. Remove from pan and cool completely on a wire rack.