Well, do you definitely want the crayons coming out of the top? You could always do sugar cookie crayons along the edge of one of the cakes. Is this the Elmo themed one? You could do the bottom cake blue, like Dorothy's fish bowl, maybe with graham crackers along the bottom of the cake. It would be pretty easy to do. Don't forget to add a Dorothy and some fishbowl decorations! Luckily her bowl is usually pretty bare...

The middle cake can be just plain white with cookie crayons all along the side.
And then the top cake could be just fun multi colored designs, like stripes, or dots, or squigglies...etc. You could either put a number of the topper, or maybe little toy figurines.
Just some thoughts....I hope they make sense. It works in my head, but that's not always an accurate tool...

