London
Composer Bareilles performed songs at Ronnie Scott’s Jazz Club in Soho, London
The pair sang "You Matter To Me" before Sara performed a rendition of "She Used To Be Mine".
The Tony-nominated musical will have its UK premiere at the Adelphi Theatre in February next year.
The piece, which is also currently running on Broadway, is based on the 2007 film of the same name starring Keri Russell. It follows a young woman in a small town who has a talent for baking pies and yearns to escape her situation.
The musical opened on Broadway in March 2016 with Jessie Mueller as the lead character. It went on to be nominated for four Tony Awards and six Drama Desk Awards, as well as a Grammy Award.
The UK production will be the first West End musical to have an all-female senior creative team, with direction by Diane Paulus (Pippin) and choreography by Lorin Latarro (Les Liaisons Dangereuses).
Casting for the West End production will be announced later this year.