Berry-Fennel Upside Down Cake
Updated: Apr 5
I've had the idea for this cake in my head for a while, and, out of curiosity, decided to ask ChatGPT to write me the recipe. I immediately noticed some glaring issues with the AI-generated recipe, but decided to bake it as it was written. I also baked my own version, but used the Robot Recipe as a starting point. I replaced the fresh fennel with fennel seed to produce a stronger flavor, swapped buttermilk with sour cream, replaced the butter with olive oil, and fixed some of the wet-to-dry ratios.
This is a very good cake. Very springy. If you're not that into fennel, I encourage you to try it anyway. It's subtle and earthy. It hits you after the berries and will make you say "hmmm!"
An 8- or 9-inch cake pan (springform is ideal, but if you don't have one, a regular cake pan will do just fine)
1Tbsp fennel seed
180g (1.5 cup, or 6oz) blackberries
170g (or 6oz) blueberries
50g (¼ cup) brown sugar
200g (1 ⅓ cup) flour
2 teaspoons baking powder
½ teaspoon baking soda
½ teaspoon kosher salt
115g (½ cup) olive oil
200g (1 cup) sugar
2tsp lemon zest (about 1 lemon)
280g (1 ¼ cup) sour cream
1 teaspoon vanilla extract
1. Prepare: First, read through the whole recipe. That’s right. Read the whole thing once through so that nothing catches you by surprise. Now, preheat the oven to 350. Grease and line an 8 or 9 inch cake pan. I like a springform pan here, but any cake pan will do. Using parchment paper on the bottom of the pan will ensure your cake comes out. 2. Arrange the fruit: Spread the brown sugar evenly on the bottom of the cake pan so it covers the whole surface. A few bald spots are okay here, or add a few more pinches of brown sugar. Arrange the berries evenly.
3. Prepare the fennel seed: Heat a dry pan on the stovetop. Once it’s hot, add the fennel seeds and toast for 2-3 minutes, shaking the pan frequently to avoid burning. Remove once the seeds start to turn golden brown and become fragrant. Grind the fennel seed in a mortar & pestle, spice grinder, with a hammer, etc. It’s okay if the seeds aren’t fully ground - some texture is welcome here! 4. Combine the dry: In a medium mixing bowl, combine the flower, baking powder, baking soda, salt, and fennel seed. Whisk for about 30 seconds to evenly distribute dry ingredients.
5. Combine the wet: In a small or medium mixing bowl, combine the sugar and lemon zest. Massage the zest into the sugar until it appears wet like sand and is fragrant. Whisk the olive oil into the sugar. I t will appear grainy. Once fully combined, add the two eggs and whisk thoroughly to combine. Add the sour cream and vanilla. Whisk vigorously for about 45 seconds. 6. Add the wet to the dry: Using a rubber spatula or a whisk, add the wet ingredients to the dry. Mix until fully incorporated and you see no more streaks of dry ingredients. You might see little lumps in your batter here, that’s okay. We don’t want to overmix so a few lumps are okay. 7. Bake: Pour the batter into the cake pan. Use the back of a spoon or an offset spatula to spread the batter evenly. Bake the cake for 40-50 minutes. Every oven is unique, so at the 40 minute mark, start to pay attention to the following indicators for doneness. We pay closer attention to the following indicators instead of the time, so if your cake has been in for 55 minutes but doesn't appear done, it's okay! Every oven is unique.
A cake is finished baking:
When you lightly touch the center of the cake, it "springs" or "bounces" back. If you can see your fingerprint left in the cake, give it 2-3 more minutes.
When you stick a toothpick into the middle of the cake, it comes out clean. If it does not, give it 2-3 more minutes.
8. Cool and flip: Once its done baking, remove the cake from the oven and let it cool for about 15 minutes. Place a plate or cooling rack over the top of the cake and flip it over, to reveal the “upside down” part of the cake.
9. Serve: It’s lovely on its own, or pair it with some whipped cream. Or vanilla ice cream!