Kouign-amann (pronounced [,kwiɲˈamɑ̃nː] Breton pl. kouignoù-amann) is a Bretoncake. It is a round crusty cake, made with bread dough containing layers of butter and sugar folded in, similar in fashion to puff pastry albeit with fewer layers. The resulting cake is slowly baked until the butter puffs up the dough (resulting in the layered aspect of it) and the sugar caramelizes. The name derives from the Breton words for cake ("kouign") and butter ("amann"). Kouign-amann is a speciality of the town Douarnenez in Finistère, Brittany, where it originated in around 1860. The strict recipe of Douarnenez requires a ratio of 40 percent dough, 30 percent butter, and 30 percent sugar. 
The Welsh equivalent is the etymologically identical Cacan menin, literally 'cake, butter'.
Though it has more than 100 years of history, in 2014, BBC aired an episode of The Great British Bake Off featuring the kouign amann, and in 2015, it had increased popularity in the United States with notable bakeries in New York, Washington D.C., Boston and San Francisco highlighting the pastry.
^Alburger, Carolyn (October 3, 2011). "Croissant, Dethroned; All Hail Kouign-Amann | 7x7". 7x7.com. Retrieved 2015-08-22. Now San Franciscans can find the rare treat at several cafes around town, and Wood has had to put a hold on new accounts because his little bakery can't keep up with the demand. So what the heck is kouign-amann, you ask? Let's start by saying your morning croissant is about to get upstaged in the pastry case.