Who makes those terrible sheet cake things that every Chinese buffet has?

Not sure but it's probably the same stuff they used in my college cafeteria. Sometimes the yellow cake with chocolate frosting had these crumbles on the top. It dawned on us, that the crumbles were just the cake from yesterday ground up and sprinkled on top. We called it "Yestercake"

Which cakes? I've searched my entire brain catalogue for Chinese cakes and I must say it was pretty empty. I didn't know there were a particularly bad type sold at school cafeterias and cheap takeaways

I'm guessing this is what they're referring to:

I've personally seen it served identically at a few different unrelated places. I'm guessing its sold pre-made, considering that the appearance is always identical.
- Oh, thanks for the image. No I've never seen that
I feel like I'm taking crazy pills. Chinese buffet sheet cake? On what planet?
- They usually have fruit, jello, pudding, and a shitty soft serve machine where I'm from lol
- Not on my planet at least, that's why I asked
- Might be a regional thing. I've seen these in a hotel in Turkey.
I am literally in actual China today and I have no idea what cake they mean.

Edit: I've seen the image below. Yeah, I don't associate that with china.

With that said I know you didn't mean it as China has no notable cake, but I can associate at least one cake with the most China thing ever. Ma Lai Gao. The one you see in every single dim sum restaurant. Kinda like sponge cake.
- I think where I live most mainstream asian restaurants don't showcase their desserts as much as their other dishes. You've just made me realise this. It's like you need to actually search for them on the menu to find them, unlike with western style restaurants which clearly have cakes and sweets on display. I recall places selling a variety of asian cakes and sweets but they're niche... This explains why my mental repertoire is so empty.
  
  Ma Lai Gao. It's on my list now, I must try this!

Chinese cakes, desserts, etc use less sugar and are generally more bland than western recipes. It is a matter of different cultures having different tastes.

I can see that.

However very little of what I've ever seen at a Chinese buffet in America has made me think of real Chinese cuisine.

I think the cakes OP is talking about are just shitty because every one of these cheap buffets gets them from Sysco.
I'll have to look into that idea! Honestly I never even imagined that these were even vaguely related to actual Chinese desserts; I entirely assumed they were just Western cake ideas, but impossibly cheap.

Like the pizza that's always on those burgers. Even less authentic than the rest of the stuff, and somehow cheaper tasting than even Cici's. (Not knocking the restaurants for that; gotta have something for the picky kids.)
- In America in particular we use a ridiculous amount of sugar in everything. People used to eating Chinese food -- like, the kind they eat in China -- in my experience are typically unprepared for it. I worked for a Chinese restaurant for a while and my boss, who was Cantonese, tried and subsequently declared a wide array of American foodstuffs to be completely inedible due to being too sweet. Including stuff we don't think of as being "sweet," like ketchup.
  
  I'd doubt the horrid sponge cake you find at the Chinese buffet is actually related to any imported Chinese confection, but it's probably made according to the sensibilities of whoever is running the place. Especially if they ever plan on eating it themselves. (You laugh at this prospect. And yet: one of my boss' favorite things to do on the rare holidays we were closed was to go to other Chinese restaurants that weren't.)
- You're almost certainly correct that it's just cheap cake. Is Betty Crocker cake really a traditional Chinese dessert? Furthermore, most buffets like this are Americanized ethnic food not traditional dishes.

Yo, I load that shit up with ice cream. I love it.

Hey, some of us like that stuff! But I have no idea

Same place that makes those thin cardboard pizzas they have in elementary schools probably.

Aramark who also serve the same food in jails and prisons.
- Or Sodexo, which is slightly better in my experience.

Aramark, Cisco foods, etc.

They’re probably frozen and thawed out for service. Like 90% of stuff served in high volume restaurants.

Sysco foods. Cisco is the router company, but some of their stuff tastes the same.
*Sysco

Cisco makes networking equipment.

Hopefully we'll get an authoritative answer from someone who works at one of those places.

But if I had to wager on it, I'd wager that they all use a similar simple cheap recipe, and it's just part of their daily routine of stuff that they make.

If you've ever paid attention to a Chinese takeout type place (I know, not necessarily the same thing) then you'll notice they all have a giant pot of this sauce/stock stuff that they use in almost every dish. Every day someone comes in and prepares a big batch of that stuff (it's made from soy sauce and a few other simple ingredients). Then just ladle it out all day as they cook up each order. They would never do this for home cooking, but for a restaurant it makes total sense.

So my guess is some poor bastard comes in early in the morning and dumps some giant box of cheap industrial cake mix into a huge mixing bowl with some other basic ingredients and then just spreads it out in a pan and throws it in a commercial oven. It's not a ton of work, and you can do other things while it's baking.

It's true a lot of restaurants outsource their baked goods and desserts, but my guess for a buffet which is operating on lean margins, they would not.

The mix is probably sold in bulk from one of the various suppliers of sundries for Chinese restaurants, which is just an entire industry. If you've ever seen the identical fixtures and trimmings at multiple Chinese takeout places in your town and thought to yourself there must be a master catalog of this junk, some kind of Chinese Store Store if you will, that's because there is.

I worked at a Chinese take out restaurant for a while. While we did not serve the ISO Standard buffet sponge cake, I can tell you a few of the following secrets. None of them are ancient wisdom.

Actually, the hoisin sauce (the thick soy sauce stuff that serves as the base for many, but not all of the sauces we'd make) was not made in a batch at the beginning of the day. We got it from a massive can bought from our goods supplier. Actually, not massive can in the singular. Cases and cases of them.

The "Chinese store iced tea" that all the homeboys in the hood loved so much was, in fact, just Country Time iced tea mix, from Costco. Mixed in a thoroughly washed out 5 gallon bucket that originally contained soy sauce. Ditto with the lemonade. Same kind of mix, both packaged into quart soup containers. It's about as "homemade" as a box of Hamburger Helper is.

On the flip side, we made all of our roll products by hand, from their constituent components except the pizza rolls, which came frozen from our goods supplier. Dumplings and wontons we also made by hand, although the dough wrappers we got from our goods supplier. The owner of our restaurant hand chopped the cabbage and so forth for the egg rolls. I would have used a mandolin for this purpose, but then I guess there's a reason I don't run a Chinese restaurant.

The sweet and sour sauce you get with your sweet and sour chicken, pork, etc. in the little quarter height soup container is roughly a 50/50 mixture of ketchup and pineapple juice spiked with an (un) healthy ladlefull of sugar. My boss indicated to me that in his opinion this was the most vile stuff on Earth, but it's what customers wanted so he'd hold his nose and make it anyway (see my other comment in here for his take on American style ketchup).

Yes, the chicken is real chicken. We got it frozen from... you guessed it, our goods supplier. Chicken is cheap in bulk, and cats are really hard to catch.

MSG went in everything. The cart between the woks contains three bowls of white powder. One is granulated sugar, one is salt, the third one is MSG. If you told us you wanted "no MSG" the cook would put less of it in your dish, but you'd still get some. Does your local takeout place have a "no MSG" badge on their menu? I'll bet they do. Our place did. That was on there just for decoration. It was a bold faced lie.

Several of the other base ingredients also inherently included the stuff (including the hoisin sauce) so it's actually physically impossible to get most Chinese takeaway dishes made while truly containing none. Curiously, none of our regular customers who claimed they were deathly allergic to MSG ever came back to us with any problem over this. (People will now attach comments to this absolutely insisting that, nuh-uh, they are in fact totally actually allergic to MSG!!!! Am I calling you a liar? Well, I'm saying it's significantly more likely that some other ingredient in there disagrees with you instead.)

The curry you make at home never quite looks like Chinese restaurant takeaway curry because ours has about two tablespoons of yellow food dye in it. Other than that it is totally the same cheap curry powder you can buy at the grocery store.

Uh, both the scallops and crab we served were imitation. That's probably not much of a secret. If you have a shellfish allergy, you can probably safely consume those. The shrimp in everything is the real deal, though. Including in the shrimp toast.

Same company that makes all the other shit at a Chinese buffet. And its all soyent green shipped over from China.