I then roughly iced all surfaces with basic icing, to make the marshmallow fondant icing stick to the cakes. I couldn't believe how easy it was to make the marshmallow fondant, and also, how easy it was to work with.
To make it, i bought a 250g pack of marshmallows, and split them into pink and white. I put one colour in a bowl, with 1tbsp of water, and microwaved for approximately 30 seconds, and stirred until it was a smooth mixture. I then measured out around 250g of icing sugar, and started mixing it into the marshmallows bit by bit. Once the mixture was starting to almost form a dough, and lose it's tackiness, I turned it out onto the bench, and kneaded the rest of the icing sugar in. I should mention that I had dusted the bench with icing sugar to ensure that the icing didn't stick. Once the icing reaches the consistency of playdough, it is ready! You can either tint it at the marshmallow stage, once it is removed from the microwave, or you can actually tint it once it has turned into icing, by kneading the food colouring through - however this takes a bit longer, and you may end up with stained hands!
From this point I separated the icing into batches and tinted them different colours. For the base icing layer of each layer of the cake, I simply tinted to the desired colour, and then rolled out to around 4mm thick, draped it over the cakes, removed any extra, and smoothed out any joins. You can smooth the joins by brushing with water, and rubbing the area with a small ball of icing, dusted liberally in icing sugar.
Once you have finished decorating, brush very lightly with water to remove any traces of icing sugar. The cat's face came out a bit soft and started to fall apart, as it was a 35 degree day, and quite warm in the kitchen. I wasn't sure whether time in the fridge would help to set it hard or not, and I didn't have time to experiment.