Before fifty years ago most of the bread used was made from oaten meal. It was mixed with a little flour and the sourest butter-milk. It was baked on a griddle or in a pot oven and sometimes the top and underneath were covered over with withered ferns called "feairn" and furze bushes. These would be set fire to and would smoulder away until the bread was cooked.
This was called smothered cake.
It was not eaten until a day after it was baked and plenty of butter was used with it.