While this cake is quite old (2 Easter's ago) I thought I would include it anyways, as it was my first (and possibly last) attempt at using homemade marshmallow cream fondant. I made the fondant using a simple recipe: marshmallows, water, and lots of powdered sugar. I microwaved a bowl of jumbo marshmallows (jumbo or mini, doesn't matter) with 2 tablespoons of water in 30 second increments, stirring in between each time as the marshmallows melt. Once the marshmallows are completely melted, stir in about half of a bag of powdered sugar so that the marshmallows aren't so sticky. Grease a counter top, or a big baking pan and cover it with powdered sugar (like you would flour if you were rolling out cookies, but use a lot more) and pour the mixture onto the powdered sugar and begin kneading the sugar into the marshmallow mixture until it has the consistency similar to dough.
Grease a rolling pin and sprinkle it with powdered sugar, and then roll out the fondant like dough, until it is about 1/4" thick. After baking and frosting the cake, (mine was a layered yellow cake with a vanilla buttercream) carry the fondant draped over the rolling pin and carefully lay it across the cake, making sure to cover the sides. Smooth the fondant down onto the cake, making sure there is no tears or wrinkles. The fondant is really sweet since it is essentially just marshmallows and sugar, but it becomes very chewy after awhile and you have to be careful when cutting the cake to make sure you get through the fondant first so that it does not tear it off of the cake.
While it made the cake look nice, it really did not seem worth all of the extra hassle and work for a non-tiered cake. I also think next time I'll just buy pre-made fondant and save half the time. For the yellow chick in the center, I used a circular cookie cutter to make an imprint on the cake for both the body and the head and then piped the fur with yellow frosting, using an orange frosting for accents and a white frosting to make a pearl border around the cake's top and bottom.