Someone posted a recipe for making fondant using 10 oz. bags of marshmellows. Does anyone remember it?
I don't know where that recipe is, but I melt the whole 10.5 ounce bag with about a tablespoon of flavoring, a couple of tablespoons of Karo syrup, and a couple of tablespoons of water. Melt in the microwave until it's all melted and smooth. I start with about 5 cups of powdered sugar, and mix it with the marshmallows in the stand mixer. I check it every 5 minutes or so, and if it is still sticky to the touch, I add a bit more powdered sugar until it is not sticky anymore. Then wrap in plastic wrap, put in a large ziplock bag and let it sit an hour or two before using it.