Edit on July 25, 2009: Starbucks has, unfortunately, decided to stop offering the gluten-free Orange Valencia Cake.
You probably already knew this, but just in case: Starting May 5th, 2009, Starbucks offers a gluten-free dessert: the Orange Valencia Cake with Almonds. You can learn more at the Starbucks blog.
You probably already know the closest Starbucks locations, so I do not think I will list all 27 Starbucks Tucson locations (according to DexKnows.com) 
