1 cup mini marshmallows
1 tbsp water
1 1/2- 1 3/4 cup powdered sugar
Place marshmallows in a standard 1 cup measuring cup and push down and pack them in. Place in a microwave safe bowl and add the water. Put in the microwave for about 45 seconds, just long enough for them to soften and puff up. Take out and stir with a spoon until it is combined well. At this point it looks kind of soupy. Then add the sugar and mix and fold until all is incorporated and it is no longer sticky. Take it out of the bowl when it gets to the point where most of the sugar is incorporated and knead it in your hands. This takes roughly about 3-5 minutes. Take a fondant roller or a regular rolling pin and roll out just as you would regular fondant. You can get this fondant almost paper thin and it also repairs easily too.
Adding color: If you want to make the whole batch of Marshmallow fondant one color then add the color (gel or paste) at the "soupy" stage. Stir it up and then add the powdered sugar. Otherwise add it after it has come together and been kneaded by hand. I use plastic gloves when I do this, because otherwise your hands are never the same! Add the coloring to a ball of fondant and knead until incorporated. You can use a very small amount of shortening on your hands (gloves), rolling pin, work surface, etc. to keep fondant from sticking. (I usually just use a sprinkling of powdered sugar on everything to keep it from sticking)
