I did a quick google search to see if someone else has stumbled upon this cob-shaped void in the universe; I was surprised at how little I found.
There was a creator that attempted to accomplish the impossible by fusing the kernels with melted chocolate. His story can be found here: http://somethingaweek.wordpress.com/2011/10/15/82-candy-corn-on-the-cob/. He was successful and made a beautiful cob of pure sugar.
I also found another attempt on youtube where a guy used icing, but ended up with a frozen block of sugar. http://www.youtube.com/watch?v=nZKeseqwaL8
I was looking for something easier, cheaper, and more fool proof.
I experimented with fondant first, that was completely unsuccessful. Then I though of gluing it together with caramel (since I had a fresh bag of that around too). Too messy and too hard.
Then, another light bulb went off.....cookie dough! Sugar cookie dough works perfectly (don't attempt with chocolate chip dough, the chips just get in the way and jeopardize structural integrity). It only took about 4 minutes to assemble and looked authentic.
Update: For those afraid of the raw eggs in cookie dough, I recommend making egg-free cookie dough instead.Here is a handy recipie I found online: http://www.food.com/recipe/egg-free-no-bake-cookie-dough-for-eating-391880
Second Update: I have received a lot of recommendations to substitute marzipan instead of the cookie dough...the choice is yours :)
Some helpful details:
I only used about 1/10 of the tube of cookie dough for the cob core(hooray for leftover cookies!). I rolled it thinner in my hands to get the half-sized cob.
I pushed the candy corns into the cookie dough only as deep as the white part., if you push them in too deep then they start to collide in the cookie dough and cause it to loose its shape. I layered the kernels by alternating the spacing each row (length-wise). As you can see in the picture, I set the rows with the kernels flat against each other, not the longer way.
Also, I only used about half a bag of candy corn ( a lot of them were broken). So you could easily make two small cobs from one bag or one impressive full-sized cob!
Its pretty stable on its own, but a quick set in the fridge really helps hold it together. It also helps to have the cookie dough chilled before pushing in the candy corns.
Now I have fixed the sugar-cob-shaped hole in my life and have a brick of sugar to eat. Although the earthy-vanilla of the sugar cookie balances out the unadulterated sweetness of the candy corn, I do not recommend eating it all at once (unless you don't want to move for a while).
I could see this being a fun center piece or a part of a candy table where guests may pick off candy corns as they like.
It was a fun experiment, and its so cheap and easy I would love to see what people can do with it. Get out there and help fill the candy-corn cob shaped holes in the universe!