Solve a mystery? what is in the filling?

Hi Steemit Friends,

Happy Sunday.

I think I have found some gems today. These pastries are ones I have had similar at Kyoto and I can't believe I found them at the store. The only thing is I am not sure what the dark item is inside but the pastry on the outside is definitely something I have tried before and it was delicious especially the green tea ones.

There was no sample to try - if anyone can tell me what is inside, that would be great.

But I know the outside is a nice pastry.