Blend butter and cream cheese with hand mixer or stand mixer just until well blended.
Gradually add sugar beating after each addition until light and fluffy. This will take 6-8 minutes total.
Add eggs, two at a time, beating just enough to blend well after each addition.
Add vanilla just until well blended.
Fold in cake flour by hand just until well blended.
Put batter in prepared pan and bake at 275 degrees. Begin checking for doness by inserting a toothpick in center after 1 hour and 15 minutes. As soon as pick comes out clean remove from oven and let cool 10 minutes before removing from pan.
Notes
3 sticks butter equals 1 and ½ cups.
Creaming step should be done at medium speed with stand mixer or medium high with hand mixer.
Pan should be prepared by greasing and flouring or using a cooking spray which contains both.
Pound cake can be made in tube pan, bundt pan or 2 loaf pans.