What size Bundt pan did you use? The large one that’s about the size of an angel food cake pan or or a mini one?

Thanks — but a) it’s hard to tell the size — number of cups — and b) it’s not a Bundt pan. I guess I will just have to experiment.

Looking at the slideshow, the ingredient list, and the number of servings, I'm guessing the mold used in the photoshoot was around 6 cups.

It's meant to be served in the baking vessel so it doesn't appear that the actual form is terribly important.

Just make the batter and then proceed from there. If it is in a mixing bowl that has an identical twin, you can pour water into the other bowl and then use a measuring cup to figure out how much volume it contains. In fact, you can use that same water in the bain-marie so there's zero waste. Then find the right size vessel for the pudding.

I usually unmold it from the Bundt pan onto a pretty platter for serving. Butter and flour the pan before steaming and it’ll pop right out.