A Colston bun is named after Sir Edward Colston and made in the city of Bristol

Bristol

Bristol is a city, unitary authority area and ceremonial county in South West England, with an estimated population of 433,100 for the unitary authority in 2009, and a surrounding Larger Urban Zone with an estimated 1,070,000 residents in 2007...

, England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

. Composed of a yeast

Yeast

Yeasts are eukaryotic micro-organisms classified in the kingdom Fungi, with 1,500 species currently described estimated to be only 1% of all fungal species. Most reproduce asexually by mitosis, and many do so by an asymmetric division process called budding...

 dough that is flavored with dried fruit, candied peel and sweet spices. The bun

Bun

A bun is a small, usually sweet, bread. Commonly they are hand-sized or smaller, domed in shape, with a flat bottom. A bun can also be a savory bread roll similar to a bap or barmcake....

comes into two size categories: "dinner plate" with eight wedge marks on the surface and "ha'penny starver" which is an individual sized bun.
The Colston Bun is traditionally distributed on Colston Day to some of the school children in Bristol by the Colston Society.