Orange Upside Down Polenta Cake

Our latest installment of Lonesome Whistle Farm polenta inspired me to experiment with this grain in desserts. Searching around, I came across a genre of recipes for Italian polenta cake made with almond meal and often with citrus. The red hues of this colorful corn reminded me of ruby red blood oranges, and its coarse texture seemed at home in a skillet, so I decide to make a rustic upside down cake in my cast iron pan.

I used an amalgam of a polenta cake from Nigella Lawson and an orange caramel layer from Yotam Ottolenghi. I have to admit to being a novice when it comes to caramelizing sugar (I should have watched this first), and tried to take a short cut by melting the sugar in the skillet, but my caramel developed some crystals in the process. Despite this setback, I persevered, because a few sugar crystals didn't seem so bad in the grand scheme of things, and really, who could resist a cake as lovely as this on one side, 

and this on the other. It had a coarse and slightly crumbly texture that suited its skillet inception, but was moist and rich and busting with orange flavor. This cake will definitely become another regular use for our polenta supply.

Orange Upside Down Polenta Cake
adapted from recipes by Nigella Lawson and Yotam Ottolenghi 

for the caramel orange layer 
1/2 cup superfine granulated sugar
2 tablespoons water
2 tablespoons unsalted butter, cut into bits
2 blood oranges

for the cake
1 3/4 sticks (14 tablespoons) soft unsalted butter
1 cup superfine sugar
2 cups almond meal/flour
3/8 cup coarse polenta
3/8 cup fine cornmeal
1 1/2 teaspoons baking powder
3 eggs
zest from 2 blood oranges

1. Preheat oven to 350°F with rack in middle. Wash the oranges and zest them with a microphone grater. Reserve the zest and cut off the peels and pith. Slice them into 5 or 6 slices perpendicular to the axis of the sections and remove any pith in the interior.

2. Make the caramel orange layer. In a small, clean, heavy saucepan, combine the sugar, water and a dribble of juice from slicing the prongs. Bring to a boil over medium heat, stirring until sugar has dissolved, and then STOP stirring. Wash down any sugar crystals from side of pan with a pastry brush dipped in cold water. Boil, without stirring, swirling pan occasionally so caramel colors evenly, until dark amber.

3. Remove from the heat and add butter, swirling pan until incorporated, then carefully but quickly pour caramel into a well-seasoned 10 inch cast iron skillet (if in doubt, oil your skillet a bit). Tilt the skillet to coat evenly and arrange the orange slices in the caramel with the largest slice in the center and other slices surrounding it in a circle.

4. For the cake, beat the butter and sugar till pale and whipped, either by hand in a bowl with a wooden spoon, or using a freestanding mixer or food processor.

5. Mix together the almond meal, polenta and baking powder, and beat some of this into the butter-sugar mixture, followed by 1 egg, then alternate dry ingredients and eggs, beating all the while. Finally, beat in the lemon zest and pour, spoon or scrape the mixture into your caramel and orange lined skillet. 

6. Bake in the oven for about 45 minutes. If the cake is cooked, a cake tester should come out clean. Remove from the oven and allow to cook for about five minutes. Place a large plate over the skillet, confidently invert the skillet and allow the cake to slide onto the plate. Allow to cool to room temperature and serve.