This one is great fun for even the youngest kids. You can even make the decoration one of the party events!

Bake your favorite chocolate cupcakes, either homemade or from a boxed mix.

Frost them with chocolate frosting, then top with a generous sprinkle of crushed chocolate cookies (Oreos work really well).

Cut the Gummi worms in half, and stick them into the tops of the cupcakes so they look like they're crawling out or burrowing in.

The kids can do as much of the decorating as their age and patience will allow, from the frosting through the worms.