You know, the pretzel thing (sometimes cracker) filled with flavored “cheese”. I just watched a special that shows them being cooked all the way through with no filling, and they say that the filling part is a trade secret.
Anyone have at least an educated guess as to how it’s done?
Injection while the dough is still warm and soft. Just like you fill a Twinkie.
The shells were clearly done baking, and just tumbling around. I’m sure there’s some sort of alignment and injection process, I’m just wondering how that might be accomplished.
They showed the development of the Combos-making machine on a PBS show. It’s not at all how you think it’s done. A central spout squirts out the filling , while an outer section pushes out the “dough”, which expands and bakes and hardens around the “filling”. Both filling and “shell” , in other words, are extruded simultaneously in a continuous feed, which is allowed to harden (at least patrtway), then is cut into segments.
It’s non-intuitive, and maybe looks as if it shouldn’t work, but you could see it happening on the film.
It’s a far cry from those TV commercials they used to run, which showed the filling sloshing luxuriously into a pre-baked shell. But you should take it as given that TV commercials don’t depict the actual production process (especially when this involves elves, although that’s not the case here). I think they built hugely oversized “shells” for that commercial.
Edit: Never mind.
Was that the PBS show that showed how the idea for a hand-held vending machine food–something like an ice cream cone full of chicken salad–ended up becoming Combos–a silly little shell with a squirt of cheese filling? It was quite a fascinating show.
The hollow pretzel bits come down the conveyor belt and are aligned, opening up, before entering the middle stuff filling room, where a bunch of guys with hand held caulk guns loaded with cheesy spooge do the filling process, tens of thousands of time every day to a high degree of precision. You’d think it’s automated, but no. 
I didn’t see the Combo’s film, but I’ve seen snacks make by extruding them under high pressure and heat which is cooked before it leaves the nozzle. They even expand because of this process as soon as they leave the nozzle. I was going to say it was an extruder being used for the Combos, but was beat to it.