Or just a chocolate cake or birthday cake hat, if you wish! I based mine on the easter egg cake from the video game "Portal". I'm also just a little obsessed with Jonathan Coulton's song from the end of the game.
Here's the easter egg cake (which is not a lie!).
And the hat:
If you like it, feel free to use the free pattern on my blog! Just please don't make any money off it, sell it or the pattern, etc. There's a whole copyright thing if you'd like to read it, but really please just don't be a jerk and we'll be fine. http://nimcraft.wordpress.com/2009/04/30/the-hat-is-not-a-lie-2/