I wanted a Barbie Doll Birthday Cake Idea for my god-daughter’s 5th birthday. After searching the web for some Barbie cake ideas, I was quite taken with the look of the fondant icing for the dress. Having never really come across this before, I asked a foodie friend for some advice. She told me about marshmallow fondant and plastic icing. I eventually made marshmallow fondant to cover the cake as it can be draped and found it a lot easier to work with than butter icing. The marshmallow fondant is also quite tasty.
I baked a cake in a Dolly Vaden tin. I also baked another square base cake as a stand. I needed 4x the mixture of my usual one layer round sponge butter cake recipe (2x for the dress part the 2x for the square base). I covered the cakes with butter icing. Two days before I decorated the cake, I made some marshmallow fondant using 450g white marshmallows and 900 g icing sugar. This was exactly enough for the skirt part of the dress. I colored the fondant with 2 drops gel coloring. I made some more marshmallow fondant using pink and white marshmallows and did not add any coloring this time. The pink marshmallows gave the fondant a slight pink shade. I used this for the bodice of the dress. I also used it to make 6 log pieces that I stuck to the cake to allow the fondant to make creases in the skirt. I measured how big the fondant circle needed to be for the skirt.
Eventually the skirt covered the square base cake as well so I decided not to cut it and rather leave it to cover the base part. I cut all the edges, including the bodice, with a zig zagged garnish knife and added some store bought flowers and pearls. My two key tips would be to allow yourself enough time to do this and also not to overdo the decorations - you can easily get carried away.