My twins love Elmo and Sesame Street so I decided to do something along that line for their birthday. After researching this site and the internet, this is what I made. I was very pleased with the results.
I used a yellow boxed cake mix and prepared two 9 inch round cakes. I baked them and let them cool overnight in the fridge. I then added a thin layer of icing to reduce crumbs. I used yellow frosting to ice them and then red icing using a flower/star tip for the edges. Using decorations purchased from Party City, I finished it off with decorations. The cake was a big hit with my twins and the family.