The combination of chocolate and peanut butter is classic. But what about dried prune jam? Prunes go so well with salty peanuts that extra layers of prune jam make this chocolate peanut butter cake simply perfect. I might be biased (this layer cake recipe is one of my first babies), but everyone who tried this cake totally loved it. I hope you will too! Enjoy it as a birthday cake, for any other special occasion, or simply with your morning coffee.
Cake Layers
It took about a year of trial and error for me to find the perfect chocolate cake layers. Or should I say, I took a year to learn how to make cake layers the way I like them? I was looking for something not overly sweet, not too heavy but still moist and with a strong structure, that can hold the shape of the cake. For some time I wasn’t even sure, that this kind of sweet spot exists!
Chocolate sponge cake
After countless iterations, I finally decided to use a sponge cake with higher eggs to flour ratio. It may sound like a dry cake, but it’s able to absorb a lot of coffee syrup after it’s baked and still keep its structure well. So the final result is light, flavorful, and moist!
Enhanced with bloomed cocoa powder
Cakes made with a foaming method (like this one) are lighter in color, because of many air bubbles in the batter. So I chose to use bloomed cocoa powder for a richer chocolate color and taste. And for some extra moisture of course.
Number and size of cake pans
I prefer baking the batter all in one pan, but you can divide it between two same-size pans if you prefer. If you do, shorten the baking time to 30-35 mins or so.
This recipe is created for a 15 cm / 6-inch cake pan, as I very rarely bake a bigger cake. You can convert it for any larger pan with simple math. Just keep in mind that it‘s a tall cake, so do not overdo it.
PEANUT BUTTER FROSTING
Salty peanut butter frosting is one of the best parts of this cake (the other bests are all the others!). And it’s super simple to make.
What kind of peanut butter to use?
Most recipes will tell you not to use natural peanut butter for frostings. Simply because oil tends to separate from it. And you know what, they are wrong! I always use my homemade peanut butter for this cake, because:
- it’s the tastiest in the world;
- oil does not separate so quickly that it could cause any problems for the cake (at least till you finish eating it);
- it always worked just perfectly for me.
I also tried making this buttercream with store-bought perfectly creamy peanut butter that contains emulsifiers (meaning, oil never separates from it), and the result was 10 times less tasty.
There are only a few things you should keep in mind when using natural peanut butter:
- Freshly made peanut butter (e.g. made a day before) is best because oil is very well mixed while making it and will take quite a long time to start separating.
- What if you don’t want to make peanut butter yourself or you’ve made it ahead of time and the oil has already separated? Beat the peanut butter separately with an electric mixer (before adding butter), to distribute the oil throughout the butter and extend the time till the oil will start separating again.
What kind of butter to use
I always prefer using unsalted butter, because it allows me to fully control the amount of salt in the final product. As this buttercream should be salty, you can use salted butter if you prefer. Just keep in mind that you will not be able to take that salt out, in case your buttercream will get too salty.
EXTRA TIPS FOR SUCCESS
- For light and fluffy chocolate cake layers, use room temperature eggs, and don’t be lazy to beat them well. Reaching the ribbon stage may take about 8 mins, but time will depend a lot on the mixer you use. So trust the look of the eggs more than the timer.
- Cut cake layers only when they are completely cooled, or they will break and crumble.
- The saltiness in the buttercream is one of the things that makes this cake so amazing. You should feel the salt, so adjust the amount of it in the buttercream according to your taste.
- Butter should be at room temperature for both buttercreams. It should feel soft, but not melty. Leave it on a counter for at least an hour before beating.
- Spend extra few minutes to check if there are no pits left in the prunes. The possibility is low, but it still exists and can ruin your jam and your day (trust me, I’ve been there!).
- Sifting cocoa powder for the chocolate buttercream is a must. If you don’t, you’ll end up with lumps of cocoa powder that will get clearly visible when covering the cake. It will ruin both the texture and the look.
- I make cake sides smooth using a cake turntable and a scraper, but you can totally improvise here. When scraping a lot, chocolate buttercream can darken unevenly. When I am happy with the shape of my cake, I fix this with an extra thin and even layer of buttercream.
Chocolate Peanut Butter Cake with Dried Prune Jam
Simply amazing chocolate and peanut butter cake enriched with coffee syrup and dried prune jam layers. Perfect as a birthday cake or to spoil yourself on a Sunday morning.
- Prep Time2 hr
- Bake / Cook Time55 min
- Rest / Chill Time2 hr
- Total Time4 hr 55 min
- Yield10-12 serv.
- Cake Tin Size15 cm / 6 inch
Ingredients
Chocolate Cake Layers
- 3 large or 4 medium eggs (180-200 g / 6,3-7 oz without shells)
- 120 g / 4,2 oz wheat flour (cake flour or plain flour)
- 15 g / 0,5 oz natural cocoa powder
- 30 ml / 1 fl oz / 2 tbsp hot water, straight from a boiling kettle
- 180 g / 6,3 oz granulated sugar
- 100 g / 3,5 oz unsalted butter
- 3 g / 0,1 oz / 1 tsp baking powder
- 1 tbsp brandy
- ⅛ tsp salt
Peanut Butter Frosting
- 250 g / 8,8 oz smooth peanut butter
- 175 g / 6,2 oz unsalted butter (softened)
- 200 g / 7 oz icing sugar
- ⅛-¼ tsp salt
Dried Prune Jam
- 300 g / 10,6 oz dried prunes
- 150 ml / 5 fl oz water (boiled and cooled)
- 20 g / 0,7 oz icing sugar
- 2 tbsp brandy
Coffee Syrup
- 200 ml / 6.8 fl oz coffee
- 2 tbsp brandy
- 2 tbsp sugar
Chocolate Buttercream Frosting to Cover the Cake
- 200 g / 7 oz unsalted butter (softened)
- 100 g / 3,5 oz icing sugar
- 50 g / 1,8 oz natural cocoa powder
- 30 ml / 1 fl oz / 2 tbsp milk
Directions
Chocolate Cake Layers
Preheat the oven to 180°C / 350°F.
Line the bottom of the 15 cm / 6-inch cake pan with the parchment paper. Leave the sides ungreased.
In a small bowl combine cocoa powder, hot water, and 1 tbsp of brandy. Mix well. You should get a melted chocolate-like consistency. Set aside to cool to room temperature.
In a separate bowl, mix flour with baking powder and salt. Set aside.
On a stove on medium heat melt the butter and keep it warm till you need to use it. Do not bring to boil.
Using a handheld or stand mixer beat room temperature eggs with the granulated sugar at a high speed till the mixture triples in size and gets a very pale yellow color. When you lift the mixer attachment, the batter should fall back in thick trails which will stay on top of the batter, remaining clearly visible on the surface for at least a few moments before slowly disappearing (ribbon stage). Beating may take about 8 mins.
Add warm melted butter and bloomed cocoa to whipped eggs and beat for a few more minutes, till everything is well combined. Scrape the bottom of the bowl with a silicone spatula, to make sure no butter or cocoa is left sitting in the bottom. The batter will get slightly thinner after this step.
Sift the flour mixed with baking powder and salt into the batter. If you’ve beaten eggs well, the flour will sit on the top and will not sink.
Fold in flour carefully using a silicone spatula or a spoon just until combined. Rotate the bowl all the time to remove flour pockets easier.
Transfer the batter to the previously prepared cake pan. Bake for 50-55 mins. You can also divide the batter between two same-sized cake pans and bake them together for 30-35 mins. Test for doneness by inserting a wooden stick in the middle of the cake. If it comes out clean, the cake is done, but if there is some wet batter on it, bake a few more minutes and test again.
After taking the cake out of the oven, leave it in the pan for a few minutes. Run a knife around the pan edges, take the cake out and transfer it to a rack to cool completely.
While the cake is cooling, prepare the buttercream, jam, and syrup.
Peanut Butter Frosting
Using a handheld or stand mixer beat peanut butter and room temperature butter for a few minutes till they get light, fluffy, and well combined. You may need to stop the mixer and scrape the sides and the bottom of the bowl a few times.
Add icing sugar and salt. Start mixing on a slow speed, then increase the speed to medium and beat for a few more minutes. Taste the buttercream: it should taste slightly salty. If it’s not salty enough for you, add an extra pinch of salt and beat a bit more to mix in the salt. Taste again.
Dried Prune Jam
Make sure that there are no pits left in prunes – cut each in half to check and remove any pits you find.
Using a blender or a food processor blend prunes with water, brandy, and icing sugar till you get a smooth consistency. It should look like a thick jam, that is spreadable but not runny. If it looks too thick to spread, add 1 tbsp of water at a time till you get the right consistency.
Coffee Syrup
Prepare coffee, add brandy and sugar and mix till sugar fully dissolves.
Stack the Cake
Cut the cake only when it’s completely cooled. If it domed a bit, cut the dome off to level the top. Split the rest of the cake into four layers of equal thickness.
Put the first layer on a cake base or a flat plate. Wrap it with acetate tape (optional) and a metal cake ring. Soak the cake layer generously with coffee syrup (4-5 tbsp).
Spread ⅓ of the dried prune jam.
Spread ⅓ of the peanut butter frosting on the top of the jam.
Put the next cake layer on top and repeat the process. Finish with a soaked cake layer on the very top.
Chill the cake in the fridge for at least 2 hours or overnight.
Chocolate Buttercream Frosting to Cover the Cake
Prepare this buttercream when you are ready to cover the cake.
Using a handheld or stand mixer beat the room temperature butter on a medium speed till it gets fluffy and lightens in color. You may need to stop the mixer and scrape the sides and the bottom of the bowl a few times.
Sift in half of the icing sugar and cocoa powder. Start mixing on a slow speed, then increase the speed to medium and beat till everything is well combined. Sift in the other half of the icing sugar and cocoa powder and beat for a few more minutes. Stop the mixer to scrape the sides and the bottom of the bowl a few times.
While beating at a slow speed, pour in the milk slowly and beat for a few more minutes till well combined.
Cover the Cake and Decorate
Remove a metal ring from the cake and peel the acetate tape off. If you did not use acetate, go around the edge with the knife before removing the metal ring.
Put the cake on a turntable and cover the sides and the top with chocolate buttercream. Smooth the frosting using a scraper.
Decorate to your liking. I used fresh plums and peanuts to decorate the top.
