Chocolate. I remember in elementary school the day to buy hot lunch in the cafeteria was when they had chocolate pudding. Back in the 1960's, everything in the school cafeteria was made from scratch on site and our cook made the best chocolate pudding. She always made extra so we could get seconds.
Now everything is made off site at a central kitchen and trucked to the school to be reheated. And things like chocolate pudding are pre-packaged not home made.
I'm guessing by your spelling of the word favorite that you are talking about it in the British or Australian sense...dessert rather than custard?
Either way...not sure of my answer, lol. Though my favorite pudding (dessert) may have been pudding (custard!)...chocolate cook and serve with the film topping.
Jelly donuts are also coming to mind! And Hostess snacks.
It's hard to separate childhood favorites from now-favorites.
One thing I had in my childhood that we don't eat now is something called Elephant Ears. I think it's more midwestern.
Chocolate pudding - which here in the UK is a chocolate sponge cake with a chocolate sauce on top. The days I got that with my school dinner were highlights for me!
Not a chocolate person. As a kid we didn't eat many desserts. My favorite was probably a cherry cheesecake recipe that my mom made for special occasions. It still is one of my favorites.
And if we're talking about pudding, my favorite is pistachio.