My family demands that I make this every holiday. I will have to admit dinner would not be the same without it. I made this up years ago and never did write it down so I decided this would be a good time to do that.
This recipe is not written in concrete so if you don't like something leave it out or add what you do like.
Heat the yams until boiling then drain. Find the potato masher and mash them with the butter so it melts. Add the cinnamon and nutmeg and stir them into the yams. (You can add chopped pecans if you want to at this point)
Start with 1/4 cup of the half and half and 1/4 cup of brown sugar. Taste it you might need more brown sugar and if it too thick you will need a little more half and half. Remember you can't take those two out so do it a little at a time. The plus side is you get to taste it before everyone else snarfs it.
Put the mashed yams into a 9x13 pan and top with a package of marshmallows. (If you have a kid around that is a good job for them.) Bake at 350 degrees for 20-30 minutes or until marshmallows are golden brown.