Grease your mixing bowl and a pyrex or glass bowl that can be used to melt marshmallows in the microwave.
Place 16 oz bag of marshmallows, 2 Tablespoons of water and 2 teaspoons of flavoring of your choice in pyrex/glass bowl coated with shortening and microwave on high for 60 seconds.
Stir. If all the marshmallows are not melted, return to microwave for approximately 30 seconds.
Stir. Continue this procedure until all marshmallows are melted.
Sift one half of the 2 pound bag of confectioner's sugar in a mixing bowl which has also been greased with shortening. Make a well in the center of the confectioner's sugar and pour the melted marshmallows.
I use the paddle attachment for my KitchenAid mixer for this first part of the mixture. Mix until all the melted marshmallows are incorporated in the confectioner's sugar. Mixture will be thick but still a runny.
Sift the remaining half bag of confectioner's sugar into the mixing bowl with the melted marshmallows. Change to your dough hook attachment as this will get extremely thick.
**Note: If you do not have a KitchenAid mixer or heavy duty mixer similar to a KitchenAid, mix this by hand. This is a very thick mixture and very hard even for a KitchenAid to mix. Sift the remaining confectioner's sugar into the marshmallows/confectioner's sugar in bowl and mix. Fondant will be very thick and have a dough like consistency.
Wrap fondant in saran and make sure no air gets to it.
It really needs to sit about an hour or so to cool down completely from the melted marshmallows. It needs to be air tight so it will not dry out.