Once the butter is light and fluffy, add 2 cups cream cheese half a cup at a time on medium speed. Once the cream cheese is fully incorporated, turn the mixer speed to its lowest setting. Add 2 tablespoons pure vanilla extract, and slowly, a quarter cup at a time, add 8 cups confectioner's sugar. Once all the confectioner's sugar is added, crank the mixer back up to medium-high speed and beat for another 30 seconds, until fully blended and fluffy.