Preheat oven to 325 degrees. Grease/spray a 10-inch Bundt pan.
Cream butter, cream cheese, and sugar. Add eggs one at a time, beating well after each. Add vanilla.
In a separate bowl, combine flour, baking powder, and cocoa. Add about half of the flour mixture to the butter mixture and beat well. Add remaining flour mixture and beat well for about 2 minutes.
Pour batter into Bundt pan. Bake for 1 hour and 15 minutes or until done.