This recipe is a key building block in our Strawberry Shortcake Sundaes. It makes more than you'll need for the sundaes; serve the leftovers as an afternoon snack, with tea or coffee.
Preheat oven to 325 degrees. Butter an 8 1/2-by-4 1/2-inch loaf pan, then dust with flour, tapping out excess. Whisk together flour, salt, and baking powder in a bowl.
In another bowl, cream butter on medium speed until fluffy. Gradually beat in sugar until mixture is light and fluffy. Add eggs, one at a time, beating well after each addition. Stir vanilla into cream in a small bowl. Add flour mixture to butter mixture in 3 batches, alternating with 2 batches of cream mixture, beating until combined.
Transfer batter to prepared pan, smoothing top with an offset spatula. Bake until a tester inserted in middle comes out clean, about 1 hour, 25 minutes. Let cake cool in pan about 10 minutes, then turn out onto a wire rack and let cool completely before serving. Cake can be stored at room temperature up to 1 week.