Caramelized Blood Orange and Polenta Upside-Down Cake

I first came across polenta cake while I was interning at Maitreya Social, an amazing vegetarian restaurant in Bristol. Over the years I’ve made countless variations of it, but this has to be my favourite version. I think blood oranges are especially delicious, but if they’re not in season, regular oranges would be a perfectly good substitute in this cake. I like to serve it as a dessert with crème fraîche, and pomegranate seeds scattered over. But you can also serve it as a teatime treat.<