Marshmallow fondant can be used to decorate cakes, cupcakes and cookies. It can be rolled out to cover cakes, and made into decorations such as bows and flowers.
If you require decorations to dry hard, you will need to leave them to dry over night. To aid in this, you can add tylo powder or something similar.
You may like the taste of marshmallow fondant more than regular fondant. A point to note is that it doesn't hold up as well as regular fondant when placed in the fridge if you decorate a cake then leave it for a few days.
It takes pretty good - Mr X says they taste like a big boss (whatever that is). It basically tastes like a marshmallow, but even sweeter.
Ingredients
4 cups marshmallows
4 cups icing sugar, sifted + extra
2 tbsp water
1 tbs vanilla extract
Method
Add the marshmallows and the water to a large microwave-safe jug or bowl. Note that the bowl needs to be larger than the marshmallows - they will expand in the microwave and you don't want to end up with a huge sticky mess caused by overflowing!
Microwave on high for 1 minute, or until the marshmallows have expanded and melted a little.
Using a spatula, stir the marshmallows until smooth. At this point you may notice that the marshmallows are not all melted - if so, return to microwave for 30 seconds, or until the marshmallow mixture is completely smooth and lump free.
Add vanilla extract and mix. If you want, you can add colour - I have successfully made dark pink, purple and blue from pink marshmallows. Of course, if you are using all white marshmallows, you can make any colour you like! Note though that if you add colour at this stage, all the fondant will be the same colour! If you want to make multiple colours, wait to add it until later!
Add the icing sugar to the marshmallows all in one go. Then start to mix with a spatula. Continue to stir until the icing sugar begins to incorporate and it starts to get hard to stir.
At this point, tip the marshmallow mixture onto a clean surface dusted with icing sugar. Then remove any jewellery from your hands and grease them well (use cooking spray for ease - or alternatively something like copra). Make sure you grease them really well - trust me!! Then get kneading, as you would with bread dough, adding icing sugar until it forms a ball.
Stop adding icing sugar once it is smooth and no longer sticky. If you add too much sugar you will find it hard to work with as it becomes stiff.
From here, the possibilities are endless!
Original recipe from about.com, found here