In the United Kingdom, what type of food is a 'barm cake'?

Barm Cake is a very soft bread roll, typically 6ins (15.24 cm) diameter, 1½ins(3.81 cm) thick. The name is now restricted to Lancashire and parts of Cumbria and Yorkshire where filled bread rolls are customarily referred to as 'barms', but seems to have formerly been more widespread as the name occurs in advertisements and news reports in Derbyshire and Northumberland'

Barm is an old term for yeast and there is some evidence that barm cakes were formerly leavened with the yeast-rich froth from brewing beer. Chips are a popular filling, sold in most fish and chip shops in the North West of England and often called a chip barm. Another popular filling in the North West, particularly Greater Manchester, is a pasty barm.