The Klimpaloon Ultimatum, Operation Crumb Cake

Phineas and the gang help Love Händel prove the existence of Klimpaloon, the magical old-timey bathing suit that lives in the Himalayas, to verify that their song, "The Ballad of Klimpaloon", is legitimate.
Isabella unintentionally admits her feelings for Phineas in a letter. Meanwhile, Doof invents an inator to help change his misfortune