Preheat the oven to 325°F (160°C). Grease a 9 x 5-inch loaf pan.
In a stand mixer, beat together the butter, cream cheese and sugar until light and fluffy, about 3 minutes. Add the eggs one at a time, beating 1 minute after each. Beat in the vanilla extract.
In a separate bowl, whisk together the flour, salt and baking powder. Gradually add the flour mixture to the butter mixture with the mixer speed on low; beat until just combined.
Scrape the batter into the prepared loaf pan, smooth out the top, and bake 1 1/4 hours, or until a toothpick inserted in the centre comes out clean.
Notes
Room-temperature ingredients: Softened butter and cream cheese cream together smoothly for a fine, even crumb.Cream well: A full 3 minutes of beating incorporates air for a lighter pound cake.Don't overmix the flour: Beat just until combined to keep it tender.Test for doneness: At 1¼ hours a clean toothpick means it's done; tent with foil if the top browns early.