It's a sort of popover, that turned and popped under.

A popover is a light, hollow roll made from an egg batter similar to that used in making Yorkshire pudding. The name "popover" comes from the fact that the batter pops over the top of the muffin tin while baking.

Food historians generally agree the American origins of the recipe, although derived from Yorkshire pudding made in England since the 17th century. They are generally served at breakfast, with afternoon tea, or with meats at lunch and dinner.

Ogden Nash• inverts the historical order of events.

Let's call Yorkshire pudding 

A fortunate blunder:

It's a sort of popover

That turned and popped under.

* Ogden Nash know best (for me) in reflections on Ice-Breaking wrote:

Candy

Is dandy

But liquor

Is quicker.

I'll just say it took two different recipes before I got it right. And now it's very easy for me.   Many cooks will say it's this or that, or it needs to be stirred just so, with this added here, and that added there. But I say, it all works, the key is the time in the oven.   And if you have a top burning oven, put a cookie sheet over it.  Oh, I'll give you the recipe I use, for my my version, but you have to email me (or comment) and you must be a subscriber!

Enjoy, and keep popping!