A wonderfully soft and fluffy peanut butter layer cake bursting with beautiful peanut butter flavour and filled with a luscious and silky peanut butter mousse cream frosting. This cake can be paired with any of your favourite fillings and frostings to become the peanut butter cake of your dreams.
It’s funny how as an avid baker you can constantly make a cake and claim it as your favourite. It’ll be this way until the next time you create a cake that you love and suddenly that cake becomes your favourite.
I absolutely adore peanut butter and love using it in desserts. Whether baked as cookies or used as a frosting, peanut butter is delicious and very versatile. There are so many different things you can make with it but a layer cake is truly the ultimate.
This recipe uses peanut butter in both the cake and the frosting. It can be tricky to incorporate it into a cake as peanut butter can be a little high maintenance and make your cake dry and dense. Achieving that perfect soft and tender crumb requires a few simple steps and some key ingredients.
- Flour: you should use cake flour in the recipe instead of all purpose or plain flour. This will make your cake softer and more delicate. Cake flour isn’t easily accessible to everyone so to achieve that same desired effect, we’re going to use a combination of all purpose flour and cornstarch.
- Baking powder & baking soda: I use both raising agents; baking powder to give a nice lift to the cake and baking soda to react with the acids in the cake. The baking soda will act as a tenderizer and produce that soft crumb.
- Butter & oil: I use a combination of the two; butter for that undeniable flavour and soft bite to the cake and oil to enhance the moisture. Using oil also creates a looser crumb.
- Brown sugar: used for flavour and it’s reaction with the baking soda to give a soft and tender cake texture.
- Whole eggs: as we are using peanut butter, whole eggs yield a nice rise to the cake and holds the crumb together.
- Sour cream: this is the most important of ingredients as this guarantees that delectable, super moist crumb. Sour cream is mandatory but if you don’t have it you can use Greek yoghurt in it’s place.
- Milk: used to loosen the batter as well as ensure the cake doesn’t become too heavy.
In terms of peanut butter, I use the regular commercial brands like Skippy or Jif as it works really well in both the cake and the frosting. I’ve not tried using natural peanut butter brands so I’m not sure if it will work the same way.
Peanut butter Mousse
Let’s talk frosting. My favourite frosting on anything is peanut butter frosting, I love it paired with literally any other flavour. I really wanted to have a peanut butter on peanut butter cake recipe in my repertoire so I decided to make a peanut butter buttercream frosting for this cake. I elevated my go-to frosting recipe by whipping up some cream to soft peaks and folding it into the prepared frosting.
The frosting is very easy to make as it’s just like any standard buttercream, with the addition of peanut butter. Incorporating the whipped cream into the buttercream lightens the frosting making the texture super fluffy and creamy, just like mousse. Don’t skimp on this last ingredient because the whipped frosting is magical in combination with the texture of the cake.
Tips for Success
- The cake comes together using a standard creaming method. This means that you beat the butter and sugar together until the mixture is pale in colour and creamy in texture. Make sure to cream the mixture long enough as this is what gives the cake it’s structure.
- Try your best not to substitute ingredients as any change can give a different result to the baked cake.
- Feel free to fill and frost the cake with other flavours such as vanilla, chocolate or caramel. I highly recommend trying it with the peanut butter mousse frosting in this post as it is truly fantastic.
- My ultimate tip for baking any cake is to cool the cakes on a wire rack for only 10 minutes. Then immediately store them in an airtight container to continue cooling completely. This technique locks in the moisture.
Enjoy this peanut butter layer cake and have fun paring it with different fillings and frostings!
Super Soft And Moist Peanut Butter Layer Cake
10 – 12servings
This recipe make a 2 layered 9 inch cake or a 3 layered 8 inch cake. It can also be made in a 9×13 inch tin.
2 1/4 cups (281gms) all purpose flour
3 tablespoons cornstarch/cornflour
3 teaspoons baking powder
1/2 teaspoon baking soda
1 scant (less than full) teaspoon salt
1/4 cup (50gms) + 2 tablespoons softened unsalted butter
1/4 cup (60mls) + 2 tablespoons oil
3/4 cup (150gms) sugar
1/2 cup (100gms) + 2 tablespoons soft brown sugar
3 large eggs
3/4 cup (180gms) creamy peanut butter
2 teaspoons vanilla extract
1/2 cup (125gms) sour cream*
1 cup (250mls) milk
- For the frosting
1/2 cup (100gms) softened butter
1 1/2 cups (380gms) smooth peanut butter
2 cups (250gms) icing sugar
6 tablespoons (90mls) milk
1/2 teaspoon vanilla extract
1 cup (250mls) whipping cream**
- Preheat oven to 180C/350F. Grease and flour cake tins and/or line with baking paper.
- In a bowl, whisk together the flour, cornstarch/cornflour, salt, baking powder and baking soda.
- In a separate large bowl, cream the butter. Add in the sugars along with 2 tablespoons of the oil and cream mixture until paled and fluffy, about 2 – 3 minutes.
- Add in the remaining oil then the eggs one at a time whisking well in between each addition. Add in the vanilla extract followed by the peanut butter.
- Add in a third of the flour mix and whisk until barely combined then add in the sour cream and whisk until just combined. Add in another third of the dry ingredients followed by the milk whisking each until just combined. Add in the last third of the dry mix and whisk until *just* combined and no more flour streaks remain. Batter will be slightly thick and fairly smooth but it’s okay if there are a few lumps, just make sure there are no flour pockets.
- Divide batter between cake tins. Bake for 18 to 25 minutes until cooked through and a toothpick comes out with a few moist crumbs or clean. Cool on a wire rack for about 10 minutes then store in an airtight container to continue cooling completely.
- For the frosting
- In a large bowl, whisk together the butter and peanut butter until combined.
- Add in the icing sugar and whisk well. Pour in the milk adding more or less until desired consistency is reached. Add in vanilla. Beat mixture until smooth, about 1 minute. Don’t over mix.
- In a separate bowl, whisk the whipping cream until soft peaks. Gently fold in the cream to the peanut butter frosting in 3 batches.
- To assemble the cake
- Once the cakes have cooled completely, you can chill them in the fridge to make it easier, place one layer onto a cake plate. Spread about 1 cup of frosting on top. Place the next layer of cake on top and evenly spread another cup of frosting on top. Use the remaining frosting to spread across the sides of the cake. You can do a crumb coat first and then frost the outside but I don’t usually do it for this cake.
- Allow cake to set for an hour before slicing. Store cake, and slices, in an airtight container for up to 5 days.
- *Sour cream is necessary for the cake, if you can’t find it then replace only with Greek yoghurt.
- **Whipping cream is also known as heavy cream or double cream.
- The frosting amount stated in the recipe makes enough to fill and frost the cakes as shown in the photos. If you like you can easily double the frosting recipe to make more.
- Please note that if making this recipe as a 2 layer 9 inch cake, the bake time will be longer. I would recommend to start checking for doneness at 20 minutes.
- Recipe by the dutch baker.