Question: Which Baroque composer was known for writing single movment sonatas? 
Context: Johann Paul Schiffelholz (13 March 1685 – 28 January 1758), was a German Baroque composer and an important composer for the variety of baroque lute called colascione, as well as writing the usual trio sonatas, etc., for the violin family of instruments.  He was born in Heideck. Mrs Philarmonica (fl.  1715) was the pseudonym of an English Baroque composer.  She published a collection of 12 trio sonatas for two violins with Richard Meares in London about 1715.  Her actual identity is unknown. William Young (died 23 April 1662) was an English viol player and composer of the Baroque era, who worked at the court of Ferdinand Charles, Archduke of Austria in Innsbruck.  The sonatas which he published in 1653 were some of the earliest sonatas produced by an English composer. Johann Jakob Greber (?  – buried 5 July 1731) was a German Baroque composer and musician.  His first name sometimes appeared in its Italianized version, Giacomo, especially during the years he spent in London (1702 – 1705).  Greber composed solo cantatas, sonatas, and stage works, including the opera "Gli amori di Ergasto" which opened London's Queen's Theatre in 1705.  He died in Mannheim, where for many years he was "Kapellmeister" of the court orchestra of Charles III Philip, Elector Palatine. Giuseppe Domenico Scarlatti (Naples, 26 October 1685 Madrid, 23 July 1757) was an Italian composer who spent much of his life in the service of the Portuguese and Spanish royal families.  He is classified primarily as a Baroque composer chronologically, although his music was influential in the development of the Classical style and he was one of the few Baroque composers to transition into the classical period.  Like his renowned father Alessandro Scarlatti, he composed in a variety of musical forms, although today he is known mainly for his 555 keyboard sonatas. Arcangelo Califano (fl.  1730s–1756) was a baroque composer and cellist.  He played in the orchestra of the Dresden Hofkapelle.  His surviving compositions include sonatas for double reeds and basso continuo. A piano sonata is a sonata written for a solo piano.  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.  The first movement is generally composed in sonata form. Jean Baptiste Senaillé (23 November 1687 in Paris – 15 October 1730 idem) was a French born Baroque composer and violin virtuoso.  His father was a member of Les Vingt-quatre Violons du Roi.  Senaillé studied under Jean-Baptiste Anet, Giovanni Antonio Piani and in Italy under Tomaso Antonio Vitali and imported Italian musical techniques and pieces into the French court.  He wrote around 50 violin sonatas.  He is most well known for a fast 2/4 movement from one of these sonatas, "Allegro Spiritoso", which has had versions published transcribed for a wide variety of instruments, from violoncello to bassoon to euphonium. The title Notebook for Anna Magdalena Bach (German: "Notenbüchlein für Anna Magdalena Bach" ) refers to either of two manuscript notebooks that the German Baroque composer Johann Sebastian Bach presented to his second wife, Anna Magdalena.  Keyboard music (minuets, rondeaux, polonaises, chorales, sonatas, preludes, musettes, marches, gavottes) makes up most of both notebooks, and a few pieces for voice (songs, and arias) are included. George Frideric (or Frederick) Handel ( ; born Georg Friedrich Händel ] ; 23 February 1685 (O.S.) [(N.S.) 5 March] – 14 April 1759) was a German, later British, baroque composer who spent the bulk of his career in London, becoming well known for his operas, oratorios, anthems, and organ concertos. Handel received important training in Halle and worked as a composer in Hamburg and Italy before settling in London in 1712; he became a naturalised British subject in 1727.  He was strongly influenced both by the great composers of the Italian Baroque and by the middle-German polyphonic choral tradition.
Answer: Domenico Scarlatti