Although the shop claimed it also sold tahin helvası (from sesame seed) I think this is of a type I tasted in Edirne, a cheese-based substance that is also called helva.
I wonder (and could someone help me out here) if it is somehow related to a type of sweet I came across in Syria, see my picture of it. I preferred the Syria one, the Turkish was still too cheesy for my taste (though I have eaten Limburger with no ill effect).