No joke.
I’m not a marshmallow fan but what I do know is store bought are disgusting. Homemade are so many worlds better… don’t waste them in a beer. use them for smores and add this to your beer: https://www.monin.com/m/toasted-marshmallow-syrup-1.html
then drink the beer with smores.
Just a thought…I believe Silver Cloud Estates sells an Olive Nation Marshmallow extract which is reportedly pretty good. I would probably add that if it were me.