I bought a carton of satsuma mandarins last week, which is way more than Will and I can eat on our own if for no other reason than we get tired of peeling pith off segments. So when I found this recipe using whole satsumas (ie: not delicately sectioned segments), I was VERY intrigued. The original recipe is attributed to Nigella Lawson, but multiple bloggers have posts about it. I probably wouldn't have tried it based on the Food Network alone, so although that is the original source, I hope you'll visit these links to others whose postings inspired me to give it a try.
I, too, used a 9" pan, and checked it at 30 minutes, but it wasn't done until about 45 minutes. Even at that point however, the outside edge was a bit dark.
I believed her when she said "leave this cake as is, no icing, no dusting of powdered sugar."
My assessment is that this cake is very good and quite easy. And although it's high-fat, it at least offers some nutrition. It's different from what you might be used to and what you might expect. And it can handle some various "interpretations." Ultimately, this version was not one I will repeat, though I certainly enjoyed it. I especially enjoyed it in a second round when I replaced half of the ground nuts for all-purpose flour and used hazelnuts in place of almonds. It could also perhaps be enhanced with a bit of spice such as ginger or cinnamon. And an attractive sprinkle of powdered sugar or dollop of sweetened whipped cream isn't going to upset the unique balance that is this cake.
Update January, 2016: So, I did repeat this cake, because I came to it through completely different means when looking for something to do with meyer lemons. I got sent to this recipe which struck a chord in my memory... turns out it's exactly the same as Nigella's recipe, so I don't know who came up with it first. But I decided to try it again with the meyer lemons. I used 6. I ground the almonds in my food processor which in the end I think is a little too coarse for my preference and I would have preferred commercially ground almonds or - as I say in my notes above - partial substitution with flour. In any case, the lemon flavor is excellent, and the batter filled an 8" pan and a 6" pan both, which I baked for 40 minutes at 375.