What is it?

I came back from Japan with 12 Tokyo Bananas and now I'm down to one. I've given one each to close friends of mine, and it's funny how 90% of them didn't know what they were. 

"Hey thanks so much," they would say. Slight pause, observing the snack. "What is it?"

"Banana filling in the inside, cake on the outside," I've gotten this question so many times I already had a ready-made answer. 

Either way, all seemed to enjoy them, and I'm happy.