Larsen made her Broadway debut in 2000 in the ensemble of
Rent. In 2002 she originated the role of Roberta in the cult Off-Broadway musical, ''
Zanna, Don't!'', for which she received a
Lucille Lortel Award nomination for Best Featured Actress in a Musical. In 2005 she again appeared on Broadway in the ensemble of
All Shook Up and in 2007 performed in the original Broadway ensemble of
Xanadu. She has also performed in
Avenue Q playing the role of Lucy the Slut/Kate Monster on National Tour, Broadway, and Off-Broadway. In 2019, The
Old Globe Theatre premiered the musical
Almost Famous, based on the
Cameron Crowe film of the same name, with additional music and lyrics by
Tom Kitt, with Larsen starring as Elaine Miller (played by
Frances McDormand in the film. Larsen is the founder of the Jaradoa Theatre Company, which combines performance with community service. In 2009 a musical based on her own life, titled
Shafrika: The White Girl, dealing with her experiences of living with a blended adoptive family, was staged at the
Vineyard Theatre. ==Stage==