I think this is Cookie. My package is actually called Biscuit Gourmand and labelled in French, since I did get it in France. And it makes sense that they translate their original japanese names for teas into both English or French, as the place of sale. Their catalogue number seems to be 5537 which googling leads to Cookie.
It fits marvelously all other descriptions of this tea on steepster, black tea, marvelous cookie, bakery type of smell, like sugar and almond and butter. My first attempt at making it, quite carelessly, because I wanted something to drink with lunch (yes, this is a weird choice, but I could not resist and it worked) and I loved it. I was struck also by how smooth the base was.
seems lovely !
It was, I really liked it! I think I might need to restock when I run out of it, already been investigating and the shipping within Europe is not unreasonable (and they let you pick 6 free samples!).