A little over a week ago, I hit publish on a four-course dinner party menu inspired by the history of the Parisian bistro. If you’re curious to read more about it, you can check out the side dish here and find the full menu over on my Substack. That menu concluded with a rich Chocolate Mousse served with unsweetened whipped cream and Armagnac-soaked prunes. And those unassuming prunes are the reason we’re all here, because without them, today’s Dark Chocolate Prune Cake with Passion Fruit Curd would not exist.
It’s best to think of this recipe as an alternative ending for those Amagnac-soaked prunes. I don’t reach for prunes very often. I buy them for something (like my Chicken Marbella Skillet), use half of them, and the other half rattles around my pantry for the rest of the time. I’m exaggerating, but you get the point. I don’t think of prunes that much because they play a very small role in my life generally. But my past, well, that’s a bit of a different story.
When I was growing up, we used to go to my Grandmother’s house every Sunday for dinner. She would typically make a classic roast dinner, followed by dessert. And if you were me, you would always hope that dessert would be her flourless chocolate cake. I loved that cake, and when she passed away, the cake went with her. She never wrote the recipe down, or if she did, we never found it. But I did know one thing. I knew the secret ingredient was stewed prunes. She always kept jars of prune baby food in her pantry, and at this point, there were no babies in the family.
Fast forward to a few weeks ago, after I wrapped my Parisian Bistro shoot, I still had half a jar of Armagnac-soaked prunes, and truth be told, I had left them in there for too long. Eating them was like eating pure alcohol. I am militant about food waste, so I knew I had to do something with it. And my grandmother’s cake rolled into my mind. I made a flourless chocolate cake batter, blitzed my prunes, and added them to the cake. What emerged from the oven was otherworldly. Deeply fudgy, rich, and sweet, but in a deep and complex way.
Okay, so the cake tasted amazing, but it didn’t look amazing. It wasn’t ugly by any means; it was just overwhelming. Naturally, frosting was the first option that sprang to mind. I knew a chocolate frosting would be an overload. This cake already has 12oz of dark chocolate in it. You can fight me on this, but I believe that you can have too much of a good thing. And yes, I do believe that includes chocolate.
I landed on a classic vanilla Swiss Meringue Buttercream because I love the contrast of a fluffy, airy frosting and a dense, rich cake. But the cake needed something extra. It needed a hit of acidity, and that’s where the passion fruit curd came in. Passion fruit is one of my favorite flavours on the planet. It hits me between the eyes every time. And I earnestly believe it does its best work when paired with dark chocolate. But I must admit, I wasn’t sure how to put all these moving parts together, then this honeycomb-esque design wandered into my mind. I have to say, I’m shocked it worked as well as it did.
To make this cake as you see it, you will need a sultan piping tip. Yes, I know. I hate special equipment as much as the next cash-strapped girl. But I promise this tip is a minimal investment, and it is so much fun to play with. I haven’t been able to stop dreaming up new designs since I got it.
This cake is incredible, but it’s not without its annoyances. For one, you have to leave the prunes to soak in Armagnac for 48 hours before doing anything. So yeah, this isn’t a lickety split recipe from the get-go. And then you have to make the cake, the Swiss Meringue Buttercream, and the passion fruit; another piece of the puzzle that also needs to sit. The plus side is that none of these components is difficult to make, and all of them can be made in advance. To be clear, I think this Dark Chocolate Prune Cake with Passion Fruit Curd is well worth the effort and journey. There’s not a lot of instant gratification here. And maybe that’s a good thing. Why can’t a dessert be a character-building exercise?
This Dark Chocolate Prune Cake is delicate when it comes out of the oven. It has nothing but eggs to support it. But when it cools, and the butter and chocolate are allowed to solidify, it becomes sliceable and sharable. If there is one piece of advice I can give you about this cake, it is this: do not take it out of its pan until it has cooled completely. Better yet, cool it completely, refrigerate it overnight, and then take the springform ring off. This cake’s crumb is so tender, it will tear something fierce if you move too quickly. Yes, another part of this recipe requires waiting. I really want you to fight for it, don’t I? Lol!
And that’s everything you need to know about this Dark Chocolate Prune Cake with Passion Fruit Curd. It’s rich, complex, and unique. And yes, it is totally worth the wait.
Enjoy!
Dark Chocolate Prune Cake with Passionfruit Curd
Ingredients
Equipment
Method
- Place the tea bags in a large resealable jar, then cover them with boiling water. Let steep for 5 minutes. Remove and discard the bags. Add the prunes to the tea and let sit for 4-12 hours.
- Drain the prunes and cover them with the Armagnac. Seal the jar and let them soak for at least 48 hours, up to a week.**
- Preheat the oven to 325°F. Grease a 9" springform pan with butter and dust the interior thoroughly with cocoa powder. Set the pan to the side.
- Place the butter and chocolate in a heatproof bowl. Place the bowl over the mouth of a small saucepan with about 2 inches of gently simmering water. Slowly melt the chocolate and butter together until no lumps remain.
- While the chocolate and butter are melting, drain the prunes and place them in a blender, food processor, or smoothie cup. *** Add a tablespoon of the sugar and blitz until smooth.
- Add the prune purée to the chocolate mixture and whisk to combine. Add the egg yolks and, again, whisk to combine. Set the mixture aside.
- Pour the egg whites into a stand mixer or a large mixing bowl. Add the salt and cream of tartar and whip on high using a whisk attachment or a hand mixer. While whisking, slowly stream in the remaining 3 tablespoons of sugar.
- Fold 1/3 of the whipped egg whites into the chocolate mixture until no streaks remain. Repeat with the remaining egg whites. Pour the finished batter into the prepared pan and smooth the top.
- Bake the cake for 40-45 minutes. The cake should still jiggle in the middle. Transfer the cake to a cooling rack and let it cool for 20 minutes before removing the ring. The cake is very delicate while hot. Let cool completely. ****
- Pour the sugar into a bowl and add the lemon zest. Rub the zest lightly into the sugar with your fingertips. Set the sugar to the side.
- Split the passionfruits in half and scrape out the pulp into a food processor. Pulse a few times to loosen the membrane around the seeds. Pour the passionfruit pulp into a fine-mesh strainer and use a spoon or a muddler to force as much juice out of the pulp as possible. You should have about 1/2 cup.
- Pour the passionfruit juice into a small saucepan. Add the lemon sugar, the eggs, the yolks, and the juice of the lemon you zested earlier. Whisk to combine and place over low heat.
- Cook the curd over low heat until it reaches 170-180°F. Pour the hot curd through a fine mesh strainer and immediately add the butter. Stir until the butter melts completely. Chill the curd for at least 3 hours.
- Take the vanilla bean and scrape out the caviar using the blunt end of a knife. Set the caviar to the side and store the pod for future use.
- Place egg whites, sugar, salt, and cream of tartar in a heatproof bowl. Place the bowl over a small saucepan with 2 inches of simmering water and cook gently while whisking constantly. Cook until the mixture reaches 185°F. This should take about 10 minutes.
- Take the egg whites off the heat and pour them and the vanilla caviar into a mixing bowl or the bowl of a stand mixer fitted with a whisk attachment. Whisk the egg whites on high (you can also use a hand mixer for this) until the mixture cools to 90°F.
- While still whipping, start adding the butter, roughly 1 tablespoon at a time. Whip until the rich and creamy frosting forms. It will look a little rough on the way to being perfect, so don't freak out.
- Transfer the Swiss Meringue Buttercream to a large piping bag fitted with a sultan tip. Pipe the frosting onto the surface of the room-temperature cake. **** Fill in the center of each frosting dollop with the passionfruit curd. Finish with shaved chocolate and serve immediately.
