Melt your mini marshmallows in the microwave until they start to puff.
Stir the water and glycerin into your bowl of melted marshmallows. Melt the mixture further if any lumps remain.
Pour your marshmallow mixture into a large bowl of icing sugar and stir with your rubber spatula until you can’t stir any more.
Once it’s too solid to stir, pour your marshmallow fondant mixture out onto a flat work surface that’s been lightly dusted in more icing sugar. Keep kneading your mixture until it all comes together.
TIP: Note: You want the fondant to have some elasticity so that the it doesn’t break. If you find your fondant to be too tough, add in some more water. Or, if it’s too runny, simply add more icing sugar to the mixture and continue kneading.
Once you’ve achieved the perfect texture, roll your marshmallow fondant into a neat ball, wrap with cling wrap and allow some time for it to rest.