Place a rack in the center of the oven and preheat to 325 degrees F. Butter three 5×3 mini loaf pans or one 9×5-inch baking pan and dust with flour. Shake the excess flour and set aside.
In a medium bowl, whisk together flour, baking powder, and salt. Set aside.
In the bowl of an electric stand mixer fitted with a paddle attachment, cream together butter and cream cheese. Stop the mixer as needed and scrape down the bowl to make sure the butter and cream cheese are evenly incorporated. Add the sugar to the butter and cream cheese mixture, and beat on medium speed until smooth and creamy, about 3-4 minutes.
Stop the mixer and once again scrape down the sides of the bowl. On medium speed, beat in one egg at a time, beating for about 30 seconds after each addition. Stop the mixer and scrape down the sides of the bowl as necessary. Beat in vanilla bean paste.
Reduce the mixer speed to low, and sprinkle in the flour mixture. Mix over low speed until the dry ingredients are fully incorporated.
Spoon batter into the prepared pans. Bake for 50-60 minutes, or until a skewer or cake tester inserted in the center comes out clean, or with just a few tiny crumbs.
Wrap tightly with plastic wrap. Loaves should last about four days.
Number of servings (yield): 3 loaves