Years ago I had Russian honey cake (??) layers of cake with a honey and cream filling. It was delicious, so I tried making some myself for Easter. It took me a whole day and it was a disaster!! And I'm very good at baking. I don't know where I went wrong!
Ooops, sorry. I said it in English while Polish recipes say it in Polish as dupa/pupa pawiana. Here you are: haps.pl/Haps/7,167251,28525123,zaskocz-najmlodszych-w-dniu-dziecka-ciasto-pupa-pawiana-bedzie.html
Eclairs, meringues and tompoozers (vanilla slices)?
More international than specifically Polish and with origins elsewhere; they've certainly been around in Britain for a century or more, and I think tompoozers were invented there or in Holland. Very much cakes not 'cookies' which are a type of biscuit, often containing chocolate chips.
Karpatka is mainly Polish though and Wuzetka (delicious, and my favourite) are specifically Polish.
I've only seen dach贸wki migdalowe in Warsaw and even there in only a few bakeries. They deserve to be better known.
Too late to edit. The thing that Dutch people call tompoezeers are slightly different to vanilla slices (sometimes tompoozers in the eastern parts of the UK). The British ones and the Polish ones are very similar however the British ones are a little lighter.
Napoleonki in Warsaw are very similar; just a slight difference in filling.
The most Polish cake ever is probably s臋kacz, although wikipaedia describes it as "Lithuanian 拧akotis or raguolis, Polish s臋kacz, Belarusian bankucha".
Either a gastro-cultural child of the Polish-Lithuanian Commonwealth, or originally Polish and eaten also in those areas that are now in Lithuania and Belarus.
Looks scary, best eaten in small quantities but very nice.
edit
Google says it either came from Queen Bona Sforza or the Yotvingian tribe round the Baltic.