Plum Polenta (Upside Down) Skillet Cake
This polenta cake–half cake, half cornbread–is built upon fresh plums and a light caramel syrup in a skillet, then finished in the oven and flipped over to reveal a plum and syrup topped polenta cake, moist and not too sweet…perfect for breakfast or afternoon snack.Jump to Recipe
Plums in my Brain
I love plums. Just look around A Quarrel of Feasts and you will find an everyday Croatian Plum Cake, a Croatian Plum Custard Tart…you are seeing a trend here, yes? Croatians love plums–our national moonshine Sljivovica is made from plums, and I have yet to scratch the surface of how many ways plums can find their way into a sweet dessert.
I have been wanting to make a skillet cake since summer began. Also, being a lover of Italian style cakes like olive oil cakes, I wanted to give the polenta cake a try. Croatians are also big fans of polenta, usually as a creamy cheesy side dish to a meat centric dish. In this cake, I was under the impression that skillet cakes were cooked entirely in the skillet. Whoops.
It’s ok though, since this recipe comes together really easily. Slicing the plums might be the most time consuming part. The cake does finish in the oven, but using a cast iron skillet makes that transition a quick one.
I love black plums, but wanted to try the lighter red plums that were in abundance at the supermarket. The result was lovely: juicy, soft, and a wonderful fruit flavor to pair with the polenta base and the sweet syrup topping (on the bottom).
Tips & Tricks
You do need a skillet. Cast iron works great, since you can pop it into an oven to bake and be fine. Just remember where it’s been when you touch the handle after removing it from the oven! In my case, my skillet was a little big at 12 inches. I need a smaller one for sure, but the recipe still works out. It’s just a little more tricky to turn the upside down part of the cake over when the skillet is that big and heavy. Be careful or find a stronger arm to help out.
- When slicing the plums, you have some choices. I first used my fancy food processor to make perfectly even and thin rounds. I overlapped them into the bottom of the skillet on top of the syrup created from sugar and water.
- The slices grew a little too thin and didn’t stick to the cake as first hoped, which is why I decided to re-make and cut the plums by hand in chunky slices, as if I were cutting apples for a Tarte Tatin. They ended up less of a protective force between the cake batter and the sugar syrup, but their presence was really substantial. Both have advantages and disadvantages. The choice is up to you…
- When making any caramel syrup, whether light or not, remember the old adage: never stir, once the sugar is fully dissolved into the water. Shake the pan from side to side, swirling the liquid so it grows light amber evenly, but never stir. The mix will be loud and cracking, then lower and quieter.
- The cake batter comes together as many cakes do: the sugar, butter, and vanilla provide the start, followed by the egg yolks and finished by alternating the sifted dry ingredients and milk. Separately, the egg whites are beaten to stiff peaks with a little sugar and are folded in by hand to the existing batter in order to lighten up the texture and weight of it.
- The plums are laid out on top of the syrup, and the batter is poured over and spread out. The cake is then finished in the oven and, after 10-15 minutes at most, turned out and over so the plums and syrup are on top. Make sure to slide an offset spatula or thin knife around the edges before turning out, and give the pan a little light shake just before you raise that pan with a prayer and a hope.
Plum Polenta Upside Down Skillet Cake
- Cast Iron or oven safe skillet
Sugar Syrup and Plums
- 5-6 plums, sliced in rounds or thicker slices
- 6 tbsp granulated sugar
- 3 tbsp water
- 2 tbsp unsalted butter
- ⅔ cup all purpose flour
- ½ cup polenta
- 1½ tsp baking powder
- ¼ tsp salt
- 6 tbsp unsalted butter
- ½ cup granulated sugar, plus 1 tbsp for egg whites
- 1 tsp vanilla extract
- 2 eggs, separated yolks and whites
- ½ cup whole milk
For the Fruit and Sugar Syrup
- In a cast iron or oven safe skillet, spray with cooking spray or grease with butter.
- Slice the plums evenly, whether in rounds or chunkier tarte tatin style slices. Set aside.
- On medium low heat, add sugar and water to the saucepan and whisk until the sugar is completely dissolved.
- Leave the sugar alone! Move skillet from side to side and/or move liquid around, but do not mix again. Once a light amber, in about 5 minutes, remove skillet from the heat and add in diced butter. Whisk vigorously and set aside.
- Fan the plum slices out, starting in the outside edge and working your way to the middle.
For the Cake
- Preheat oven to 375 degrees.
- Sift dry ingredients into a bowl and set aside.
- In a mixer or bowl, combine the butter and sugar until light and fluffy, about 2-3 minutes. Add the vanilla extract, followed by each egg yolk, allowing to beat for a few seconds in between.
- At a lower speed, alternate adding the dry ingredients and the milk: dry-milk-dry-milk-dry.
- In a separate bowl, whisk the egg whites to soft peaks. Add in the tablespoon of sugar and whisk again until stiff peaks form. By hand, fold in the egg mixture in three installments, making sure to whip up and circle, not knocking the air out of the batter.
- Pour the cake batter onto the sliced plums and syrup in the skillet and spread it evenly over the whole skillet.
- Bake for at least 45 minutes, or until top is golden brown and toothpick comes out totally clean. It may take up to 50 minutes or more depending on the size and depth of your skillet.
- Let the cake cool for no more than 10-15 minutes in the skillet. Slide an offset spatula or thin knife around the edges, give the skillet a little shake, place a large platter or plate over the skillet and flip the skillet over onto the plate. Watch the handle, it is still hot! Give the skillet one more little shake and remove…hope for the best, but if you loose a couple plum slices, fret not–you can stick them right back on top.
- Serve for breakfast or dessert or any time of day with creme fraiche or confectioners sugar.