Love Yorkshire pudding. To me it must be made with beef drippings. If you use butter the tins you have made what I think of a popovers. If you use vegetable oil, such as Canola, I am not sure how you categorize it.
You can use them as a sweet - I guess the Brits would call it using a pudding to make a pudding. Put on a blueberry or strawberry syrup with some of the fresh berries along. Sprinkle with some powdered sugar and add a garnish,maybe a few mint leaves.
I think you could do something with bananas, but I can't even stand the smell of them so will not even attempt a recipe idea.
Of course there are tons of savory dishes. You can cover or fill them with all sorts of things. Try a Google.
Good luck.