Preheat oven to 325°F.
Brush loaf pan with oil or coat with butter. Place a tablespoon of granulated sugar in the loaf pan and rotate it around to coat the inside, like is normally done with flour.
On medium speed, beat the butter and cream cheese for about 2 minutes.
Add in the sugar, increase the speed to medium-high and beat for 2 more minutes.
Blend in the vanilla and buttermilk.
Beat in eggs, one at a time, just until incorporated; do not over mix!
On low speed, blend in the cake flour, scraping down sides as needed.
Pour batter into the prepared loaf pan and smooth out the top using a rubber spatula.
Place on rack on top third of the preheated oven for 75-80 minutes.
Toothpick inserted in center should come out clean if done.
Place on a cooling rack. Slide an offset spatula or knife around the edges and allow it to cool in pan for about an hour. Then, gently turn pan on its side and tap to loosen and remove pound cake; it should come out easily. Allow it to completely cool on rack before slicing.