There is quite a lot of kneading in this recipe. Whilst it’s perfectly possible to do this by hand, a dough hook attachment on your mixer will make things a lot easier.
Sift the sugar into the mixer’s mixing bowl and add the white vegetable fat.
Place all the marshmallows into a second large heatproof bowl along with a tablespoon (15 ml) of water. Microwave for 30 seconds. Stir and microwave for another 30 seconds. Continue in 30-second segments until the marshmallows have dissolved.
Scrape the melted marshmallows into the bowl on the mixer. Attach the dough hook and mix the ingredients together for 3–4 minutes. You may need to stop the mixer and scrape the sugar off the sides a couple of times.
You may well find it best to finish the dough off by hand. Liberally dust your work surface with a little more icing sugar and tip the mixture out. Continue kneading until you have a soft pliable ball of dough then double wrap in plastic wrap and leave for a few hours before use.
Place the marshmallows into a large heatproof bowl along with a tablespoon (15 ml) of water. Microwave for 30 seconds. Stir and microwave for another 30 seconds. Continue in 30-second segments until the marshmallows melt. It should take between 1 ½ and 2 minutes.
Tip 3/4 of the sugar on top of the marshmallow mixture and fold it in using a spatula or long metal spoon.
Grab a large handful of the white vegetable fat and grease both your hands and your worktop. Tip the mixture out and knead it as you would bread, pulling and pushing the dough and continually folding it over.
Add the rest of the sugar as you go and keep re-greasing your hands. By the end you should have used up all the fat and sugar. It could take up to 10 minutes of kneading and it will be messy but you will have very soft hands afterwards!
Double wrap it in plastic wrap or a polythene food bag. The fondant will be very soft at first and is at its best if allowed to sit and mature for a few hours before use, ideally overnight.