This is my son's 5th birthday cake. He wanted an alien/outer space/rocket themed party, so this is what I came up with. The cake had to travel with us 45 minutes away, so I didn't want it to be too complicated and have more of a chance for decorations to fall off. The best part was the inside of the cake. I wanted to do something really fun and unexpected, so I made the inside rainbow and it was a hit.
Cake is covered in fondant with fondant alien and letters. Border is buttercream.
The smash cake was copied from his napkin.
The hostesses picked out 

