Melt 1/2 cup butter in a small saucepan over medium heat. Stir occasionally and cook until the milk solids turn brown and give off a nutty fragrance, 15 to 20 minutes.
Combine the remaining 1/4 butter and cream cheese in a mixing bowl.
Pour the browned butter into the mixing bowl and set aside for about three minutes, letting the warm butter soften the cream cheese and cold butter. Scrape the black seeds from the vanilla bean and add them to the bowl.
Add the bourbon and mix on low speed until smooth.
Gradually add the confectioners' sugar and cream, alternating between the two, until the proper consistency is reached. If the frosting is too soft for decorating, refrigerate it for about half an hour before using.
