Question: Which Baroque composer was known for writing single movment sonatas? 
Sentence (from "Piano sonata"): Piano sonatas are usually written in three or four movements, although some piano sonatas have been written with a single movement (Scarlatti, Liszt, Scriabin, Medtner), two movements (Haydn), five (Brahms' Third Piano Sonata) or even more movements.
Relevant evidence: No