I want to go over a few marshmallow making basics for those of you who want to go ahead and make them yourself.
Many of the recipes that I've read say to grease your pan... DO NOT grease your pan. This makes the bottoms of your mallows, well, greasy. Eww. I line my pan with parchment and dust with a mix of 50/50 Sifted cornstarch and powdered sugar.
You MUST have a candy thermometer to make real marshmallows (sugar free doesn't require this step) you Must boil the sugar mixture to 240°f. Too cool and it won't fluff up, too hot and as soon as it starts to cool you'll have a broken mixer.
Be very careful when pouring the hot sugar into the mixer! Start on low and once all the molten sugar is into the bowl, then turn the speed up. Otherwise it will splatter and you will get burned.
Time your mixing! 12 minutes is what you need to get a good fluffy marshmallow. Once it's done don't walk away or you're gonna have a bowl of marshmallow that you can't spread into a pan. This rings especially true for the sugar free ones, they begin to set up almost automatically.
Don't use a hand mixer for making marshmallows. The first time I made marshmallows all I had was a hand mixer, and there was marshmallow all over me, in my hair, on the walls, on the ceiling and not only that... I broke the mixer before they were even finished.
Let the mallows rest in the fridge, if you leave them out chances are they're not going to set properly.
When they're finished you can freeze them in storage bags, just make sure they're dusted well with powdered sugar and cornstarch so they don't stick.