With thanks to PBaser, Chris Gibbins.
I had mixed feelings about sharing this recipe because it has so much sugar in it, but it was so easy to make and so delicious that I threw caution to the wind.
When I saw the recipe I remember that I had some leftover almond flour (from my macaron phase) in the freezer and this would be a good use for it. Turns out I didn't have 250 grams, but I did have sliced almonds, so I ground them to make up the difference. I think my oranges might have been too big because the cake, which I baked for 55 minutes, not 60 because the top was getting too brown, was a bit too moist. Served it with vanilla ice cream since I didn't have creme fraiche.
This recipe from Fine Cooking magazine states that it's supposed to be very moist and pudding-like: https://www.finecooking.com/recipe/orange-almond-cake
Here's the photo that inspired me. https://pbase.com/chrisg_62/image/171673960