we wouldn't have a plethora of threads every year saying "WTF shall I do with this enormous marrow?"
Because things that are delicious get eaten again and again, they don't get discussed. Nobody starts threads entitled "WTF shall I do with this great big roast chicken?" or "WTF shall I do with all these peaches?" do we?
The answer to all your marrow queries is to ram it firmly into the compost heap, and use it to grow something edible next time!