Birthday Cake - repeating stars in M&Ms

This cake is pretty self-explanatory.  Just make a star in the center (lightly pressing a star-shaped cookie cutter works well), in the M&M color of your choice, and then repeat over and over.  I've done this cake a few times.  It looks best if the outlining M&Ms are close together--especially that second and third level.  So don't worry about even numbers or anything--just keep them almost touching.  You can keep all the outlines solid, but the girls really like how this one kind of drapes down the sides.