Flatkaka (Icelandic pronunciation: ​[ˈflaːtˌkʰaːka], lit. "flat cake") or flatbrauð ([-ˌprœiːθ], lit. "flat bread") is an Icelandic unleavened rye flatbread. Flatkaka is soft, round, thin and dark with a characteristic pattern from the pan. It is assumed that the Icelandic tradition of baking flatbread goes back to the settlement of Iceland in the 9th century. Historically, Iceland moss (Cetraria islandica) was sometimes used as a supplement because of a lack of grain on the island.