I had two birthday parties this year, won't do that again!! My daughter who was turning three wanted a dinosaur cake. The second cake was a purple Triceratops Cake. Lots of fun to make!!
First I made a Marshmallow fondant, I found the recipe on line. I made it a week ahead of time as explained in the recipe so that it has time to set-up.
For the Purple Stegasauras: I used two boxes of cakes. I used two round cakes, a square cake, and a small glass mixing bowl for the head. I cut both round cakes in half and used frosting to glue them together to make the body, with the flat side down. I used a piece of thin cardboard cut out to make the plate on the back of its head. I used the square pieces for the feet and tip of the nose, and I used the mixing bowl for the main part of the head.
First I baked the cake, and let it cool. Once the cake is cool, color your fondant with food coloring. Use latex gloves so you don't stain your hands. Make sure to separate out the fondant into the amount you need for each color. Once cake is cool, use butter cream frosting as the "glue" for the fondant. Spread a moderate layer all over the cake, including the cardboard plate. Roll the Fondant out with a rolling pin, corn starch works well to keep it from sticking, once you have it to the desired size to fit over your cake, roll it onto a rolling pin and put it over your frosted cake. I used a pizza cutter to cut off the excess fondant. If you don't get any frosting on the extra fondant you can easily re-use it.
I wish I would have covered the cardboard plate with a separate sheet of fondant, it would have been a lot less messy. For the decorations I used set aside fondant that I colored and I used cookie cutters for the shapes and flowers, and a garlic press for the grass.
If I do it all over again I will freeze the cake sealed in several layers of plastic wrap, then cut the cakes and frost while still frozen, it would allow for easier sculpting, and less falling apart for the little pieces of cake. Once you have the fondant on the cake do not refrigerate, it will make water spots on the fondant, so make sure to decorate one day ahead of time and seal the cake up to set overnight.