Layers of moist banana cake are stacked with a smooth, creamy salted caramel and a peanut butter Swiss meringue buttercream. The cake is finished off with buttercream stripes for a classic bakery look!
Hi! Happy Saturday! I hope you are keeping well and safe. I wanted to pop on here and share a recipe I made a few weeks back - this banana layer cake with a salted caramel filling and a peanut butter Swiss meringue buttercream. I have made this flavour combination a bunch of times before but just never for the internet. The most recent time was for my friends Rosie and Luke’s wedding back in NZ when we were home, where I did a whole cake table with 6 cakes rather than a traditional tiered cake. The concept worked out so well - we were able to do a whole bunch of different flavours, and I didn’t have the stress of worrying about stacking a cake. They were all a huge hit, and I had some requests to share the banana cake with you, so here we are! I paired it with a salted caramel filling and a vanilla bean Swiss meringue buttercream for the wedding, but today I went a little rogue and went with a peanut butter Swiss meringue buttercream instead, and finished it with some stripes for a super cute, slightly retro finish.
The cake is one I think most New Zealand kids grew up on - a take on the classic from Edmond’s cookbook (which is the baking bible of NZ). We typically pair it with what we call “shitty chocolate buttercream”, which isn’t shitty at all, but just the one that we grew up on, which is a mixture of powdered sugar, cocoa powder, a teeny bit of butter, and some boiling water. It’s a childhood classic, and is Richard’s fave to this day - on more than one occasion he’s scraped buttercream I’ve made off a cake to replace it with the shitty chocolate one. It’s pretty damn yum, although I really don’t think you can beat this banana, salted caramel and peanut butter combo. xx
A few wee tips:
I made this a few weeks ago before we went into lockdown so shared it with a lot of friends. If you were looking for smaller quantities you could halve the banana cake recipe and bake it in 6” pans instead for a smaller cake!
Swiss Meringue buttercream freezes super well - just make sure that you rewhip nicely when you have defrosted it. I like making the full amount of buttercream even if I am halving the cake recipe because it is a great thing to have in the freezer.
This buttercream is a little looser than some because of the peanut butter, but will firm up nicely in the fridge. It still worked great for stacking the cake!
Salted Caramel keeps in the fridge for at least a few weeks, and in the freezer for much longer. I love stirring it into coffee.
Here is a little tip for you when it comes to dividing up batter - weigh your mixing bowl and note down the weight! If you know how much your bowl weighs then you can weigh the whole bowl, full of batter, and then subtract the weight of the bowl from the total weight.
I made the stripes with an icing comb! It looks super fancy but it’s not too tricky to do. You just have to make sure that your initial coating of icing is nice and thick, and that you freeze the cake down well after carving out the ridges. This means that when you add the accent colour, it is super easy to smooth down because you are working with a frozen cake. Don’t be afraid to fill the ridges right up with the accent colour! I didn’t put quite enough buttercream aside when I did it and it was a major error.
Mix and match this cake with any of the buttercreams here on the site - there’s so many!
Made this recipe and love it?
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A note on salt and oven temperature
It is important to note the type of salt that is called for in a recipe. I use Diamond Crystal salt throughout my recipes - if you use a different sort of kosher salt or regular table salt you will need to adjust accordingly as some salt is 'saltier' than others. Morton's salt is twice as salty, so you will need half the quantity. Same goes for a regular table salt. I am working to get gram measurements throughout my recipes for salt but still getting there.
All oven temperatures are conventional unless otherwise stated. If you are baking on fan / convection, you will need to adjust the temperature. An oven thermometer is a great investment to ensure that your oven is the correct temperature.
Using the double / triple function in the recipe card
You will notice that there is a '1X' '2X' '3X' button in my recipe card. This can be used for doubling or tripling a recipe. However, please note that this only doubles the ingredient quantities in the ingredients list and NOT in the method. If there are quantities or pan sizes in the method of the recipe (for example weigh out 150g brown butter), you will need to scale this number manually. It will also not change the baking time in the recipe so you will need to adjust this yourself too. It is always a good idea to read through a recipe fully before doubling it just to check this. If you would like to scale this recipe or convert for another pan size, use my calculator!
Tools and equipment
For a list of my go-to tools and equipment, I have a post you can refer to here.
Why is this recipe in grams?
I post my recipes in grams as it is the most accurate way to bake. Cups are not only inaccurate but they vary in volume worldwide. There is no way for me to provide one cup measure that works for everyone. However, posting in weight fixes this issue. If you would like the recipe in cups you are welcome to convert it yourself via google, but please do not ask me to do it for you as I am not comfortable providing a recipe using a method that I have not tested. Baking with a scale is easy, accurate, and also makes cleanup super simple. Here is the scale that I use if you would like a recommendation! Here's to accurate baking!
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Banana Layer Cake with Salted Caramel Filling and Peanut Butter Swiss Meringue Buttercream
- Prep Time: 60 minutes
- Cook Time: 45 minutes
- Total Time: 1 hour 15 minutes plus cooling and chilling time
- Yield: 8" layer cake 1x
Description
Layers of moist banana cake are stacked with a smooth, creamy salted caramel and a peanut butter Swiss meringue buttercream. The cake is finished off with buttercream stripes for a classic bakery look!
Ingredients
Banana Layer Cake
- 315g unsalted butter, at room temperature
- 440g sugar
- 5 very ripe bananas (about 520g worth of banana), well mashed
- 5 eggs, at room temperature
- 1 tsp vanilla bean paste or extract
- 75g whole milk
- 2 ½ tsp baking soda
- 600g all-purpose flour
- 2 ½ tsp baking powder
- 1 tsp kosher salt
Salted Caramel Filling
- 200g granulated sugar
- 90g unsalted butter, at room temperature
- 120g heavy cream, warmed
- 1 tsp vanilla bean paste
- 1 Tbsp Flaky sea salt
Peanut Butter Swiss Meringue Buttercream
- 250g egg whites
- 400g sugar
- ¾ tsp salt
- 1 tsp vanilla bean paste
- 900g (8 sticks) unsalted butter, cut into cubes
- 300g smooth peanut butter
Instructions
BANANA CAKE
- Preheat the oven to 350°f/180°c. Grease three 8” cake pans, and line with parchment paper on the bottom.
- In the bowl of a stand mixer fitted with the paddle attachment, or in a bowl with an electric mixer, cream butter and sugar until light and fluffy. Add bananas and beat until incorporated. Add eggs one at a time, ensuring bowl is well scraped down and mixture is well combined.
- Heat milk in the microwave, or a small pan until boiling. Add baking soda to milk, and add to the mix, mixing until well combined.
- Sift flour, baking powder and salt, and add to the mixture. Mix briefly until just combined. Divide the mixture between the prepared pans (I like to do this by weight - see notes).
- Bake the cakes for 35 to 45 minutes, checking for doneness after 35, or until a skewer inserted into the centre comes out clean.
- Cool in their pans for 15 minutes then turn out onto a wire rack to cool completely.
SALTED CARAMEL FILLING
- Place the sugar in a medium sized heavy bottom saucepan. Heat on medium, stirring constantly. The sugar will start to form clumps, then begin to melt.
- Cook until is it amber in colour, then remove from the heat and immediately add all of the butter. Be careful as the caramel will bubble rapidly. Once the butter is incorporated, add the cream and whisk well to incorporate. Stir in the salt and vanilla, and pour into a glass jar. Allow to cool completely.
PEANUT BUTTER SWISS MERINGUE BUTTERCREAM
- Place the egg whites, sugar and salt in the bowl of a stand mixer or a heat proof bowl. Place over a pot of simmering water, ensuring that the water does not touch the bowl.
- Heat, whisking constantly, until the mixture registers 160˚f / 70˚c on a thermometer and the sugar has dissolved. Carefully transfer the bowl to the mixer, and fit with the whisk attachment.
- Whip the egg whites on high until they are snowy white and fluffy, 8-10 minutes. Add the butter one chunk at a time. The mixture may look curdled - but just keep mixing! Once all the butter is incorporated, mix on high for a further 10 minutes. Add the vanilla and mix until incorporated.
- Once the buttercream has finished mixing, and is smooth and silky, add in the vanilla bean paste. Mix for a further 2-3 minutes, then switch to the paddle attachment and mix on low for one minute to remove any air.
- If you are making stripes on your cake, remove about 350g of the buttercream. Add the peanut butter to the remainder of the buttercream and mix well to combine. If you are not doing stripes, add the peanut butter to all of the buttercream and mix well to combine.
ASSEMBLY
- Level off the cake layers. Transfer some of the peanut butter buttercream to a piping bag fitted with a medium round tip - this will be used to make a buttercream dam to hold in the salted caramel between layers.
- Secure one of the layers of cake to a cake board or cake turntable using a little buttercream. Add about ½ cup of buttercream onto the first layer of cake, and smooth using an offset spatula. Create a buttercream dam using the buttercream in the piping bag by piping a ring of frosting around the outside edge of the first layer. Fill in the ring with some of the salted caramel, spreading to the edges.
- Place the second layer of cake onto the first, pressing very lightly to secure, and sealing the joins with a thin layer of buttercream.
- Repeat the layering process - add ½ cup of buttercream, make a dam, fill with caramel, then top with the third layer of cake - I like to put this one upside down to ensure that the top of the cake is flat. Return the rest of the buttercream in the piping bag to the bowl with the buttercream.
- Crumb coat the cake - to do this, apply a thin layer of buttercream over the surface of the cake, and smooth with a bench scraper or icing smoother. Refrigerate the cake for 30-45 minutes, until the crumb coat has set. To ice without stripes (see notes): Cover the cake with a second, thicker layer of peanut butter buttercream. Smooth. Decorate as desired.
- To ice with stripes: Apply a thick layer of peanut butter buttercream, and smooth completely, ensuring that there are no holes and it is completely smooth. Chill 15 minutes. Using a warmed icing comb (run under hot water then dry), go around the cake, creating grooves in your buttercream. Make sure that the grooves are sharp edged and deep - you may have to do a few passes to ensure this.
- Freeze the cake for 30 minutes, then, using the reserved vanilla buttercream, place into a piping bag, and snip a hole off the end. Pipe buttercream into the grooves. Do not be afraid to overfill slightly. Once you have filled all of the grooves, smooth the cake using a warmed cake scraper, wiping between passes. Smooth off the top - the cake will be frozen so instead of scraping in toward the centre of the cake, I use my spatula to cut off the excess icing. Chill the cake for 10-20 minutes. To finish in the style that I have, place the remaining buttercream into a piping bag fitted with a Wilton 1M or other open star tip, and pipe a shell border design on the cake.
- Store leftovers in the fridge either covered or in an airtight container. If you want to freeze cake, Freeze it until the buttercream is set (30 minutes or so), then wrap very tightly in plastic wrap and store in your freezer.
Notes
Cake adapted from "Edmonds Cookbook"
Keywords: banana cake, salted caramel, layer cake, peanut butter, swiss meringue, striped buttercream
AMAZING! It was absolutely perfect. Thank you so much for sharing!
★★★★★
Yayyyy you are so welcome!
Hi Erin, this looks amazing! Would the caramel be the right consistency to use to swirl into a brownie? i.e. gooey enough so it doesn't set too solid when baked?
Hi! Yesss it's like a thick salted caramel sauce! It would likely work great!
Amazing! Can you please upload some pictures on how you achieve to get this perfect white stripes? I thing it would be very useful many of us. Thank you!
★★★★★
Hi! I have a full tutorial in my IG highlights of this process 🙂
Hi Erin,
You mentioned halving this recipe for a 6 inch cake which is something I've done with other cake recipes before, provided they use an even number of eggs. Do you have any thoughts on the best way to manage half of 5 eggs?
Many thanks, this looks delicious and I love the banana peanut butter combo.
Hi! You can whisk one up, weigh it, and use half! Keep the other half for an egg wash 🙂