Is Japanese kasutera the same foodstuff as Korean kastera? The Japanese term カステラ (kasutera) and the Korean term 카스테라 (kastera) are etymologically derived from the Portuguese "Pão de Castela". But does "kasutera" and "kastera" refer to the same foodstuff, or a different foodstuff?

KOREAN CASTELLA CAKE says:


  I’ve come to the conclusion that Koreans use “kastera” to describe
  almost every type of baked product that’s Western in origin.


Castella = Kastera = Kasutera says:


  These baked products are a cheap, guilty indulgence -- they are good
  -- but I don't consider them "genuine" Japanese kasutera, which I have come to understand is not as spongy and comes in a rectangular shape.


Are they the same foodstuff, or are they different foodstuffs? Would it be more logical to say "I prefer kastera over kasutera", or would "I prefer the way Koreans do kastera over the way Japanese people do it"?
There is a particular baked good called kastera in Korea, but they pretty much use the term as a generic name for any Western-style sweet cakes (source: my Korean mother-in-law). So the answer is yes and no. You will find a kastera equivalent to Japanese kasutera, but it is a subset of the kastera set.

The closest comparison I can think of would be the term "barbecue." It would very specifically mean slow-smoked meat in certain regions of the United States. In other regions, "barbecue" is a bigger tent, and includes, among other things, anything that is cooked on a grill.