Well, this must be the biggest baking disaster of my baking career. Or should I say, Baking Hobby. Geez. The picture explains all. My advice? Don't buy the cheap cones because I think what happened (or part of what happened) was that the batter soaked right through the cones before they had a chance to bake. And I guess I overfilled a little? But instead of puffing over the top nicely like it was supposed to, it poured over the sides. Broken cone edges (even small pieces) apparently don't help either.
What a mess.