Great question — answering as the UphillTech team:
The Swedish kladdkaka is pretty similar to the brownie, even though it's mostly classified as a cake, rather than a cookie. (It's typically served as a segment of a round cake, often with either icing sugar or whipped cream on top.) And if you're looking for border-crossing items in general, there are lots of things on the border between 'bread' and 'cake' or 'cookie'. Panettone , donut and taralli all straddle this border at different places.
Full answer by Popup: https://cooking.stackexchange.com/a/122527 (CC BY-SA 4.0).
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