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A rich, moist gluten free banana cake that keeps well and improves in flavour over time. It’s perfect for cake decorating, iced with your choice of buttercream or ganache (and fondant if you like!), or for eating by itself, by yourself, in bed with a fork. No judging! ❤
It’s embarrassing to admit, but after years of cake decorating, I stopped enjoying eating cake. I didn’t hate it, and every now and then I’d eat some offcuts. But I never wanted to sit down and eat a slice of cake.
But, during that time, if you stuck a piece of gluten free banana cake in front of me, I would devour it and quite possibly go back for seconds. I don’t know what it is about banana cake, but I just can’t say no.
Even now that I’m not doing as much decorating and have started enjoying cake again, banana cake is one of my favourites, and I think it always will be.
This gluten-free banana cake recipe makes a cake that is all the things we love about banana cake. It’s (cringe alert!) moist, buttery, fluffy but not too light, and of course, banana-y. Which isn’t a word, but too bad. It is what it is.
The texture of this banana cake also makes it a great gluten free cake recipe to use for lightly carved cakes. I wouldn’t do a full-on 3D cake with it, but it does work well for cakes that need a bit of shaping. For more information on carving gluten free cakes, check out my gluten free cakes for cake decorating post.
Right, that’s enough intro, let’s get into it.
How to Make a Gluten Free Banana cake
GF Banana Cake Ingredients
The ingredients for the cake are pretty straightforward. Here’s what you’ll need:
- Gluten Free Flour – I use my favourite homemade gluten-free flour blend, but you can use your own favourite store-bought or homemade blend. If you use a different flour than I do, your results may not be exactly the same as mine, but it is a forgiving recipe so it should work well with most flours.
- Xanthan Gum – This helps bind the cake together in place of gluten. You can read more about it in the gluten free flour post linked to above. If you use a store-bought gf flour blend that contains a gum ingredient, you can omit the xanthan gum from the recipe.
- Baking Soda – I don’t think there’s anything I need to say about baking soda, right? It’s baking soda.
- Butter – I usually just use regular salted butter in this recipe. If you only have or prefer to use unsalted butter, or if regular butter where you live is very salty, then you can use unsalted butter + add a pinch of salt.
- Sugar – We’re using white sugar in this recipe. I like to use caster sugar in baking so that’s what I use in this cake, but because we’re using weight measurements, you can use the same weight of regular white granulated sugar instead.
- Vanilla Extract – I love vanilla in everything sweet, but if you don’t have any on hand, then just leave it out. You can also use vanilla paste instead of extract.
- Eggs – Use large eggs for this recipe.
- Sour Cream – I think sour cream is a ✨magic✨ ingredient in gluten-free baking. It adds extra moisture and extra fat, which makes for an amazing cake texture. I haven’t tested the cake with low-fat sour cream, so I recommend using the full-fat version.
- Bananas – The star of the show! Just like with banana bread, this is the place to use your super dark, overripe bananas. The more ripe the banana, the better the flavour. Having said that, I also make this sometimes with less ripe bananas (see the ones I used for this cake in the images above and below), and the cake still works just fine. Leaving the cake overnight before eating it will help develop the banana flavour further. Don’t use underripe/green bananas, but bananas that are anywhere on the scale from yellow to black will work just fine here.
We’ll be measuring the mashed banana by weight, so the exact number of bananas may vary depending on their size and how ripe they are (the riper the banana, the smaller it gets). This is usually around 4 bananas for this recipe, but it’s a good idea to have an extra one on hand just in case if you can.
My top tip for quickly mashing bananas – especially ones that are still a little on the firmer side – pop ’em in a deep bowl and use a potato masher. Easy.
Making the cake batter is pretty straightforward. You’ll be creaming butter and sugar, then adding the eggs. Then the combined dry ingredients get added alternately with the mashed bananas, and finally, we mix in the sour cream.
At this stage, it’s best to work quickly to get the cake batter into the cake pan and into the oven, as the sour cream will start to react with the baking soda immediately and we want to make the most of those air bubbles!
She’s not the prettiest looking cake, but just wait ’til you taste it.
Icing and Decorating the Cake
I chose to fill this cake with dark chocolate ganache and cover it with a combination of the dark ganache and some white chocolate ganache that I tinted yellow. Ganache is a great choice if you’re using the banana cake to make a tiered (or otherwise highly decorated) cake.
But you can fill and decorate your own gluten free banana cake with whatever icing you desire. Cream cheese frosting is a popular choice with banana cake. Caramel Swiss meringue buttercream would also be delightful.
Call me basic if you like, but my all-time favourite way to eat banana cake is how my mum used to make it when I was a kid – just with a simple chocolate icing made with icing sugar, cocoa, a little bit of butter and some hot water to make it spreadable.
So to actually decorate this cake, I made some dark chocolate ganache and some white chocolate ganache that I tinted yellow. I filled the cake with the dark chocolate ganache, then spread more of that round the bottom of the cake, and used the yellow ganache to cover the rest of the side and the top of the cake.
If you’re new to ganache and want some step-by-step instructions, you can check out my How to Ganache a Cake post for step-by-step instructions, and my How to Colour Ganache to learn how to tint ganache any colour.
To finish it off, I pressed some chocolate sprinkles around the bottom of the cake and topped it with a couple of cute little mini cake toppers from Design at 409.
How to Store the Cake
Just like banana bread, banana cake tastes its best 1-2 days after baking. Which makes this a great make-in-advance cake, and also means it’s great for decorating using a 3 day timeline. By the time you eat the cake, it will be at peak banana flavour intensity.
To store the un-iced cake, let it cool then wrap in plastic wrap and place in an airtight container. In cooler weather, it will be fine at room temperature. If you live somewhere very hot or humid, or want to store it for longer, it may be best to pop it into the fridge or see below for tips on freezing the cake.
The iced cake should be stored in an airtight container unless it is covered with fondant, in which case it should be kept in a clean cardboard box or cake box until it’s served, then any leftovers can be stored in a container.
Can You Freeze Gluten Free Banana Cake?
You sure can. In fact, it will generally make the banana cake even moister, and if you want to carve the cake it will also make that a bit easier too.
Once the cake has cooled, wrap it well in plastic wrap (you can either wrap the whole cake, or cut the cake into layers and wrap each layer separately). Place into an airtight container or resealable plastic bag, and pop into the freezer. It should keep well for at least 2-3 months.
To defrost, take it out of the freezer and leave it fully wrapped until it has defrosted.
As always, if you’re new to gluten free cake making, or you’ve been asked to make a gf cake, then please have a look through the checklist below and have a read of my Gluten Free Cakes For Decorating post for more information on safe baking and a ton of gluten free baking tips.
- 300g gluten free flour*
- 1 ¼ teaspoons baking soda
- ½ teaspoon xanthan gum**
- 480g-500g mashed banana (approx. 4 large bananas)
- 150g butter, at room temperature
- 330g caster sugar (or granulated sugar)
- 2 teaspoons vanilla extract or vanilla paste
- 3 large eggs, at room temperature
- 150g sour cream
- Heat oven to 170°C. Line the sides of a 7" round cake pan with a tall collar of baking paper and line the base with a circle of baking paper too.
- Sift the gluten free flour, baking soda and xanthan gum into a medium bowl, and whisk to combine well. Set aside.
- Mash the bananas well, and weigh out 480g - 500g. Set aside.
- Beat together the butter, sugar and vanilla extract using a stand mixer or handheld electric mixer until light and fluffy.
- Whisk together the eggs in a small bowl or jug, then add them gradually to the butter mixture, mixing to combine between each addition.
- Add in roughly half of the dry ingredients and half of the mashed banana, and mix on low speed to combine. Add the other half of the dry ingredients and mashed banana, and mix again on low speed.
- Mix in the sour cream until just combined, scrape down the sides of the bowl and give it one last stir by hand to make sure it's all combined.
- Working quickly, pour the batter into the prepared cake pan, and smooth the top.
- Bake for 1hr 15 - 1hr 30 minutes, or until a skewer inserted into the centre of the cake comes out clean. If you're not sure, see this post for tips on checking if a cake is done.
Let the cake cool for at least 30 minutes before removing it from the pan to finish cooling.
Banana cake improves in flavour after a couple of days. To store the cake, wrap it in plastic wrap and place it into an airtight container. If you want to freeze the cake, pop the airtight container into the freezer and freeze for 2-3 months. Allow it to defrost while still wrapped and in the container, to keep the moisture in.
Fill and decorate the banana cake as desired.
* I use my favourite homemade gluten-free flour blend, but you can use your own favourite store-bought or homemade blend. If you use a different flour than I do, your results may not be exactly the same as mine, but it is a forgiving recipe so it should work well with most flours.
** If you're using a store-bought flour blend, check the ingredients list to see if it contains a gum ingredient (usually xanthan or guar gum). If it does, you can omit the xanthan gum from the recipe.
I have given a weight range of 480-500g of banana in this recipe because bananas vary in weight and I don't like wastage. Any amount between these two weights will work just fine.
Decorating the Cake
To decorate the gluten free banana cake in this post, I used 850g of dark chocolate ganache (630g dark chocolate + 220g cream) and 650g of white chocolate ganache (520g white chocolate + 130g cream). I tinted the white chocolate ganache yellow using Colour Mill 'lemon' oil-based colouring.
A cream cheese frosting or a buttercream like salted caramel meringue buttercream would also be amazing with this cake.
Whichever icing you choose, make sure you check that all the ingredients are gluten free!