There is a special dish in France that is ALL about the marrow. it's called Pot-au-feu.
Pot-au-feu (French pronunciation: "pot on the fire") is a French beef stew.According to the chef Raymond Blanc, pot-au-feu is "the quintessence of French family cuisine, it is the most celebrated dish in France.

It is an amazingly good dish!

https://en.wikipedia.org/wiki/Pot-au-feu

See the pic on this link.
https://www.seriouseats.com/2018/03...ch-classic.html
It's the classic with big bone cut cross-section and that's where the marrow is.