Preheat oven to 325 degrees.
Butter and flour a standard bundt pan, 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 softened butter and cream cheese on medium speed. Stop the mixer occasionally to scrape down the bowl to ensure even mixing. Add the orange zest and sugar to the butter and cream cheese mixture, and beat on medium speed until smooth and creamy, about 3 minutes.
On medium speed, beat in one egg at a time, beating for one minute after each addition. Stop the mixer and scrape down the sides of the bowl as necessary. Beat in vanilla extract and orange juice.
Add dry ingredients all at once and beat on low speed until completely incorporated.
Pour batter into prepared pan. Bake for 40 - 50 minutes, until a skewer inserted in the center comes out clean, or with just a few crumbs.