Penny bun

The size of the loaf could vary depending on the prevailing cost of the flour used in the baking.[1] The nursery rhyme London Bridge Is Falling Down has a version which includes the line "Build it up with penny loaves".[3] The expression "penny bun" is Cockney rhyming slang for one, sun and son.[4] "Penny bun" is also the common English name for the cep (French), or Boletus edulis, an edible basidiomycete mushroom.[5] "Cockle to a penny bun" is British slang for racing odds of 10 to 1.
Boletus edulisEnglandone old pennyAssize of Bread and Alenursery rhymeLondon Bridge Is Falling DownCockneyrhyming slangmushroomfungustrufflesBritishList of buns