We gush about chocolatey stouts, so why not stouty chocolate? This chocolate stout cake is a doodle to whip up (no creaming butter step!), and the extra complexity of the stout really sets the moist cake apart. The slightly boozy buttercream adds a nice flourish, but the lightly candied kumquats are the real highlight. If you're at all a fan of citrus and chocolate, this might just be your dream cake...
This recipe was an accident. When kumquats start appearing in my local stores I'm always reminded of this excellent kumquat dessert that I made years ago--maybe 2014? I remember it as being from the first Tartine bakery cookbook (highly recommend it!), and I was sure it was a cake, with stout, chocolate, whiskey, kumquats, and pecans. It turns out... I totally misremembered it. In fact, it didn't even exist. But I became so invested in this false memory that I decided to make it a reality!
I'll soon be sharing more about the accidental development of the recipe on my substack, but if you're really just here for the chocolatey goodness, read on!
Chocolate + Stout
Again, I ask you: where is the love for stouty chocolate?? The natural chocolate notes of a classic stout (like Guinness, which is what I bake with and drink) make it a natural choice for pairing with chocolate cake. The malty flavors of the beer add excellent depth to the chocolate flavor. You know how many chocolate cake recipes add a shot of espresso or strong coffee to enhance the chocolate flavor? The stout works in the same way, just more complex and interesting (and yummy).
If you're not a fan of chocolate and citrus then you'll not be interested in the kumquats. I quite like the combo, personally. Chocolate naturally has similar flavor compounds to many fruits, including citrus and berries. Pairing dark chocolate with citrus illuminates the natural citrus aromas present in chocolate. Plus, kumquats are a joy to eat--you can eat the skin, if you didn't know!
A bit of extra booziness helps balance the sweetness of the cake and candied kumquats, and it's also just yummy! You could also skip the booze and just do vanilla.
I personally really enjoy a cake that doesn't require a stand mixer. It's much easier to whip eggs and sugar until pale than it is to cream butter, so while it's very doable by hand, I generally whip out my dinky (but beloved) hand mixer to speed things along.
Melting the chocolate and butter in with the beer makes everything easy peasy, just make sure you let the mixture cool before adding the yogurt, and before adding everything to the egg-sugar mixture. You don't want to accidentally cook the eggs!
"This chocolate stout cake looks good, but it's a lot of steps. Can I skip anything?"
I know what you mean, and yes. Three components is a lot for a casual cake project. In my opinion you should skip the buttercream, if skipping anything. The real complexity and yumminess come from the pairing of chocolate stout cake with candied kumquats. The frosting is, ahem, just icing on the cake.
"How do I make this cake ahead?"
I recommend baking the cake and letting it fully cool before wrapping it tightly and popping it into the fridge. It'll last a few days this way if wrapped well. Bring it completely to room temp before serving. The frosting can also be made ahead and stored in the fridge, but you may need to re-whip it to get some fluff back. The kumquats can easily be made several days in advance and stored in an air-tight container in the fridge.
"How do I make this at high altitude?"
Ah yes, a constant struggle. My best advice is to consult a resource like King Arthur's high-altitude baking guide, and remember that adaptations are not one-size-fits-all. Adjusting sugar content might be ideal for one recipe, but adjusting egg amounts might be better for another.
Chocolate Stout Cake with Whiskey Buttercream and Candied Kumquats (6-Inch)
For the Chocolate Stout Cake
- 100 grams (3½ fluid ounces) Guinness or other stout beer
- 100 grams (7 tablespoons) butter
- 30 grams dark chocolate, chopped
- 20 grams (3 tablespoons) natural cocoa powder
- 55 grams (¼ cup) whole Greek yogurt or sour cream
- 1 large egg
- 140 grams (¾ cup packed) dark brown sugar
- ½ teaspoon vanilla extract or vanilla bean paste
- 110 grams (¾ cup + 2 tablespoons) all-purpose flour
- 1 teaspoon baking powder
- ¼ teaspoon baking soda
- Pinch kosher salt
For the Whiskey Buttercream
- 85 grams (6 tablespoons) salted butter, room temperature
- 85 grams (¾ cup) powdered sugar, sifted
- Pinch kosher salt or fine sea salt
- 20 grams (4 teaspoons) heavy cream
- 1 tablespoon bourbon or whiskey
For the Candied Kumquats
- ½ cup white sugar
- 1 tablespoon light corn syrup, Optional, See Tips below
- ½ cup water
- ½ cup sliced Kumquats, seeds discarded
- Before You Begin:Lightly grease a 6-inch cake pan with 3-inch tall sides. Line the bottom with parchment.Preheat your oven to 350°F with a rack in the center position.
- Step 1In a small saucepan over medium-low heat, combine the beer, butter, chocolate, and cocoa powder. Cook gently until the butter and chocolate are melted, then whisk until smooth. Remove from heat and let cool to room temperature, then whisk in the yogurt.
- Step 2In a large bowl, combine the egg, brown sugar, and vanilla. Beat by hand or with an electric hand mixer until pale and fluffy, about 3 minutes. In a separate bowl, whisk together the flour, baking powder, baking soda, and a pinch of salt. Alternate adding the flour mixture and chocolate mixture to the eggs, gently whisking between each addition.
- Step 3Pour the batter into the prepared cake pan. Bake until the top is springy and firm when lightly pressed, and a skewer comes out clean, 40 to 45 minutes.Cool in the pan for 15 minutes, then tip the cake out onto a rack and cool completely before frosting.
- Making the ButtercreamWhile the cake bakes, combine the room temperature butter with the powdered sugar and salt in the bowl of a stand mixer. With the paddle attachment, mix on low until the sugar is completely incorporated, then increase to medium-high and whip until light and fluffy. Decrease back to low and drizzle in the cream. Once incorporated increase the speed and whip until fluffy. Repeat with the whiskey, decreasing the speed to drizzle in and incorporate, then increasing the speed until the buttercream is fluffy.
- Making the Candied KumquatsIn a small saucepan, dissolve the white sugar and corn syrup (if using) in the water over medium heat. Add the sliced kumquats, reduce to medium-low and gently simmer until the kumquats look translucent, 10 to 15 minutes. Remove from heat and let cool in the syrup.
- Assembling the CakeSpread the buttercream over the top of the cake in an even layer. Spoon the kumquats evenly over the top of the cake. Include some of their syrup for a little bit of extra flavor.
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