This is EASY! And CUTE!
Get a pack (or two) of pre-made chic chip cookie dough. Press into a circle/pizza shape. While slightly warm, spread a thin layer of peanut butter on the top. Drizzle with fall m&M's, gummy worms, candy corn, etc. Then make a white icing "cobweb over it all. It is really different and very good. Have fun!
The official recipe can probably by found on the Kraft website, but you really can't mess this up in any way.
***FOUND IT!*** This O. uses sugar cookie douhg, but I used chocolate chip dough and peanut fall M&M's...
http://www.pillsbury.com/Recipes/ShowRecipe.aspx?rid=15308