Preheat oven to 350°F. Grease a 4 x 10-inch loaf pan.

Beat butter and sugar in a large bowl with an electric mixer until light and fluffy, about 3 minutes. Add eggs, one at a time, mixing well after each addition. Beat in vanilla.

Stir together flour and salt in a medium bowl. Add to batter. Mix gently until flour is blended.

Pour batter into prepared pan and bake for 60 to 70 minutes, until a knife inserted in the center of the cake comes out clean.