I also was really, really surprised at how round I got it in the end because it did not start that way. I was really struggling to get the shape for a while. Weirdly, the second one I baked I had a much easier time with the shape (as I had more practice by that point, of course) but it didn't get quite as much rise in the oven. I'm wondering if it had more to do with the toppings, as it had quite a bit of ham and pineapple on that one.