[iraldir]

It's actually a specialty from belgium / north of France called speculoos, biscoff being just a brand of that type of biscuits that managed to export them worldwide.

In the north of France where I lived for a while, it's an absolute staple akin to what peanut butter is to an american maybe or Matcha to a Japanese. Speculoos butter is spread on bread, lots of pastries are speculoos flavoured etc.