Chocolate Upside Down Cake
Rich, fudgy, ultra-moist chocolate cake is topped with sliced plums, for the most delicious Chocolate Upside Down Cake - perfect for your Stranger Things watch party. Demogorgons beware!
Servings: 10 slices (approximately)
Ingredients
For the Plum Topping:
- 450-650 grams (1 - 1.7 pounds) ripe plums about 5-7 plums
- 29 grams (2 Tablespoons) unsalted butter cubed
- 100 grams (½ cup) light brown sugar
For the Cake:
- 113 grams (4 oz) bittersweet chocolate chopped
- 43 grams (½ cup) black cocoa powder or Dutch-processed cocoa works too*
- 1 teaspoon espresso powder optional
- 115 grams (½ cup) boiling water
- 113 grams (½ cup) buttermilk** at room temperature
- 56 grams (¼ cup + 1½ teaspoons) vegetable oil or any flavorless oil
- 2 large eggs + 1 extra yolk separated when cold and brought to room temperature
- ½ teaspoon white vinegar
- 1 Tablespoon vanilla extract
- 200 grams (1 cup) light brown sugar sifted if lumpy
- 97 grams (¾ cup) all-purpose flour
- ½ teaspoon baking soda
- ½ teaspoon salt
Instructions
Prepare the Topping:
- Prepare a 9x2-inch (23x5cm) cake pan by spraying with cooking spray and lining with parchment paper on the base and sides of the pan. Set aside.
- Slice the plums into approximately ¼-inch (0.6cm) slices. Try to keep the slices an equal thickness.
- In a small skillet or saucepan, melt the butter and 100g brown sugar together until melted and combined. Transfer to prepared cake pan, spreading across the base evenly.
- Arrange the sliced plums across the base, placing in concentric circles with the slices overlapping slightly (or in more of a flower pattern, for the Demogorgon look). Set aside.
Make the Cake:
- Preheat oven to 350°F / 175°C.
- In a small heatproof bowl, place the chopped chocolate, black cocoa powder, and espresso powder (if using). Pour the boiling water over the top and cover. Set aside for 5 minutes, then whisk until smooth. Set aside to cool until it's about room temperature (set in the fridge if needed).
- In a large bowl, combine the buttermilk, oil, eggs, egg yolk, vinegar, and vanilla. Whisk to combine.
- Once the chocolate mixture has cooled, add this to the egg mixture, whisking to combine. Use a rubber spatula to scrape down the sides of the bowl.
- Add brown sugar, flour, baking soda, and salt. Use a rubber spatula to combine, ensuring the sides and bottom of the bowl are incorporated too. Do not overmix.
- Pour the cake batter over the top of the arranged plums. Tap the cake pan firmly on the countertop a few times, to release any air bubbles.
- Bake for 40 - 50 minutes, or until the cake is set and a toothpick inserted in the center comes out with just a few moist crumbs.
- Place cake pan on a wire rack and allow to cool for 30 minutes before inverting on to a cake platter. Serve with vanilla ice cream, whipped cream, or by itself. Serve warm or cool (it's delicious both ways!).
Notes
Storage: Once completely cooled, store cake in the fridge inside an airtight container or covered well with plastic wrap. Cake will stay moist for at least 4 days.
* The Cocoa: Black cocoa will give the most impressive-looking Upside Down vibes, but Dutch processed cocoa powder will work instead if needed.
**Buttermilk: Real buttermilk is my recommendation here, but sour cream (brought to room temperature) will work just fine instead if needed.
Demogorgon Decoration: If you're making this cake for your Stranger Things watch party, arrange the plums in more of a flower pattern (to look like petals), leaving an empty round space in the middle. You likely won't need quite as many plums, but feel free to slice them a little thicker, to ensure they keep their appearance after baking. After the cake has cooled, poke slivered almonds (you'll need about 1/4 cup) around the edge of the flower pattern you made with the plums, and the middle of the empty space, to make it look like the Demogorgon's teeth.