Ok, thanks for all your answers!
@Iron, yes, I've seen wodka being poured on the sponge bit for birthday cakes, but the fillings on a tort aren't always made with fat either. Look at the tort urodzinowy recipe I linked to. The filling and topping don't contain any butter etc.
Tort is an elaborate cake with layers and nice topping.
Yes, this is how my friend makes cakes. She makes one large cake and slices it into 3 sponge layers as in your pic. In the UK, sponges are often made in sandwich tins instead.....hmm, gives me an idea, maybe clash of cultures thread should be revived........then she puts whatever filling she wants in, and usually decorates the top with icing in whatever design someone has asked for.
Maybe the sand cake recipe is what she thinks is for making tort with? Because she never refers to her cakes as tort, just either cake or biszkopt.
Thanks to fat content, this cake is more delicate and fluffier.
The biggest difference I have noticed is that without fat, the sponge is a lot drier, but then I am obviously comparing it with UK sponges.
Now has anyone made Kołacz ? I love it but it looks to be a bit of a pain to make....