ALL DOLLED UP: For their joint birthday party at Los Angeles hot spot Tangier last Saturday, Lara Shriftman and Tamara Beckwith hosted a Barbie-themed fete. Guests were instructed to come “dressed as your favorite Barbie or Ken.” Most guests — including Daniella Rich, Lady Victoria Hervey, Courtney Wagner, Sarah Wynter, Claudia Mason, Casey Johnson, Samantha Kluge and Nicole Ritchie — took the invite as a license to be creative, because most of the dolls who came were not models found on store shelves. “Zoe Cassavetes is a New York Mom Who Can’t Get Laid Barbie and I’m Bad Girl Barbie,” Shriftman giggled. “But this wig is driving me nuts,” sighed Cassavetes, from beneath her short black bob. Not to be outdone, China Chow came dressed as a limited-edition Chanel Barbie, “from Asia,” she added. Alas, guests Leonardo DiCaprio, Matthew Perry and Aaron Eckhart came dressed as themselves.