Use this to decorate your next cake.
If you are using food coloring, add the color before you add the powdered sugar.
Add marshmallows and water to a large bowl and microwave in increments, stirring after the first minute and then after 30 second intervals, until marshmallows are melted and smooth.
Add powdered sugar slowly. This will be sticky at first, but when you get close to the end of the second bag of powdered sugar, you should be able to remove from the bowl and knead until it is firm. Tip: put shortening on your hands so when you knead it, it won’t stick to your hands. Wrap in plastic and allow to sit overnight. Roll out and use.
You can make two cakes from this one recipe. Store the leftovers in a ziploc bag. When ready to use, microwave until soft enough to roll out.