Question: What type of club was the Hasty Pudding Club, founded by Charles Macomb Flandrau?

Context paragraphs:
Hasty Pudding cipher: The Hasty Pudding Cipher (HPC) is a variable-block-size block cipher designed by Richard Schroeppel, which was an unsuccessful candidate in the competition for selecting the U.S. Advanced Encryption Standard (AES).  It has a number of unusual properties for a block cipher: its input block size and key length are variable, and it includes an additional input parameter called the "spice" for use as a secondary, non-secret key.  The Hasty Pudding cipher was the only AES candidate designed exclusively by U.S. cryptographers.

Hasty pudding: Hasty pudding is a pudding or porridge of grains cooked in milk or water.  In the United States, it often refers to a version made of ground corn.  Hasty pudding is notably mentioned in a verse of the early American song "Yankee Doodle".

Radcliffe Pitches: The Radcliffe Pitches are a premier all-female a cappella singing ensemble at Harvard University, founded in 1975 at the Hasty Pudding Club.  The group is made up of 12 to 14 Harvard undergraduates who perform at Harvard and internationally on the group's various tours.  During their tours, the group has travelled within the U.S. and to international destinations including Bermuda, Spain, England, France, Germany, China and several other countries.  The Pitches also perform regularly on the Harvard campus; they can be heard at large concerts in Sanders Theatre and smaller gigs including The Annual Breast Cancer Awareness Jam alongside other all-female ensembles in Cabot Café.  Other notable performances include appearances at the 1993 inauguration celebrations for President William Clinton and the Hasty Pudding Man of the Year awards.

Hasty Pudding Man of the Year: The Hasty Pudding Man of the Year award is bestowed annually by the Hasty Pudding Theatricals society at Harvard University.  It has been awarded since 1967 to performers deemed by the society members to have made a "lasting and impressive contribution to the world of entertainment."

Charles Macomb Flandrau: Charles Macomb Flandrau (1871-1938), author and essayist, was born on December 9, 1871 in St. Paul, Minnesota.  He was the son of Judge Charles Eugene Flandrau and Rebecca Blair Flandrau.  He attended school in St. Paul and graduated from Harvard University (1895), where he was a student of Charles Townsend Copeland.  He was editor of the Harvard's "Monthly" and the "Advocate" and a member of the Hasty Pudding Club and The Delphic Club.  He taught English Literature at Harvard College (1895-1896), tutored overseas (1896), and was an editor for "The Youth’s Companion" in New York City (1897).

Hasty Pudding Club: The Hasty Pudding Institute of 1770 is a social club for Harvard students.

The Harvard Krokodiloes: The Harvard Krokodiloes are Harvard University's oldest "a cappella" singing group, founded in 1946.  Four members of the Hasty Pudding Club at 12 Holyoke Street, popular for its all-male, burlesque musical theatre productions, began singing popular hits of their time in four-part harmony.  The Krokodiloes, deriving their name from the ancient Greek word for crocodile, "krokodilos", now consists of twelve tuxedo-clad undergraduates who sing songs from the Great American Songbook and beyond.

Hasty Pudding Theatricals: The Hasty Pudding Theatricals, known informally simply as The Pudding, is a theatrical student society at Harvard University, known for its burlesque crossdressing musicals.  The Hasty Pudding Theatricals was described by John Wheelwright in 1897 as a "kindly association of men of all ages in a gay evening of simple enjoyment".  It is a comedy show.

Hasty Pudding Woman of the Year: The Hasty Pudding Woman of the Year award is bestowed annually by the Hasty Pudding Theatricals society at Harvard University.  It has been awarded annually by the society members since 1951 to performers deemed to have made a "lasting and impressive contribution to the world of entertainment."

Benjamin Darrow: Benjamin Darrow (born 14 November 1868) was a lawyer, politician and author.  He served as a District Attorney in New York City around the turn of the century, was a prominent Deist and later nominee for Mayor of New York.  Darrow was born in Liberty, New York.  He attended Phillips Andover preparatory academy.  He spent his undergraduate years at Harvard University, wherein he gained membership to the prestigious Hasty Pudding Club, after which he went to Yale Law School.  Darrow famously prosecuted the Phelps-McMurphy case and was subsequently elected District Attorney for Kings County, the Borough of Brooklyn, New York.  He died a month short of his forty-third birthday in October 1911, after being run over by a wagon while crossing Bedford Avenue.  He was a close friend of famed journalist Samuel Hopkins Adams.

Supporting paragraphs: Charles Macomb Flandrau Hasty Pudding Club
Answer: a social club