Been a while since I saw the videos, but they do it the same way as with other jams.
Boil the cones or fruit in some water and sugar.
The cones become soft (they are the young and unopened cones) and I’m guessing the flavour is similar to the smell of pine tree sap.
I just had a look and the channel I originally saw the video on has a Canadian flag on it.
So most likely a north American thing, but might show up in other places.
Oh, had a look online and it says it is somewhat common in Europe, like Northern Italy but originates from Eastern Europe and Russia.