I don't really know any Slovenian but I do know that Blejska Kremna Rezina translates as Bled Cream Slice (or possibly cake I've seen both written down). As you can tell from it's name it is the local speciality. In fact it was first cooked in the Park Hotel, which is where I am straying, back in 1953.
I'm tempted to try and make these slices when I get home. From a quick hunt of the web this looks like a promising recipe.