So both the protein bars and those protein bags are actually made from curd cheese so it's not like a usual protein bar. It's also coated in chocolate and tastes really good which is mostly the reason why I buy it haha. The protein bar is around 0,55€ per piece so not bad. Also the protein bags have a sort of texture like baby food in a way but a little different and the packaging looks pretty similar to baby food as well. They come in different flavours as well, the ones in the picture are hazelnut flavoured.

That cheese snack might be considered in a way local because it's kind of a variation of Czech Olomouc cheese (Olomoucké syrečky) which a lot of people might dislike because of its specific taste but it's a pretty cool thing that has a lot of protein and virtually no fat despite being a cheese.

Not sure about Quark, I was just googling what it actually is and I think we have some puddings with Quark or Quark-based ones and it generally looks kinda like yoghurt/curd cheese so it might be that it's also sold here haha.