He is most famous for the elaborate religious spectacle-pantomime The Miracle and the screenplay for the celebrated 1930 film The Blue Angel (Der blaue Engel), which made a star of Marlene Dietrich.

In 1898 he journeyed Greece together with the poet Max Dauthendey and two years later joined the excavations at Pergamon led by Wilhelm Dörpfeld, Alexander Conze, Theodor Wiegand, and Paul Wolters.

At the same time, he continued his poetry, maintaining a lively exchange with Stefan George, André Gide, August Strindberg, Rainer Maria Rilke, and Gabriele D'Annunzio, whose 1901 play Francesca da Rimini he translated into German.

Vollmöller and his brother Hans Robert also had been working as aircraft designers; four prototypes were built until 1910, a motorised aeroplane is today on display at the Flugwerft Schleissheim aviation museum.

The Miracle retold an old legend about a nun in the Middle Ages who runs away from her convent with a knight, and subsequently has several mystical adventures, eventually leading to her being accused of witchcraft.