I’ll begin this post by saying how great this banana bread is. With the rich muscovado sugar, lots of moisture from the bananas, and a beautiful chocolate-vanilla swirl that makes it just that little bit prettier, it’s easy to make gluten free and a fabulous way of using some of those sad-looking bananas in the fruit bowl. Plus, it’s dairy free as well.

Gluten-free marbled banana bread

Having said that, I’ll continue by noting that this cake began with a disaster. I’d just got in from work; Greg’s parents were coming to tea the next evening; and I wanted to make something nice for a pudding. Banana bread – speedy, easy and reliably awesome. Marble it, and you make it that little bit awesomer.

Gluten-free and dairy-free marbled banana breadI was tired, and trying to get the bread in the oven before tea was ready. There I was, mid-marble and happily spooning pretty patterns of chocolate and vanilla banana batter into a cake tin, when a devastating realisation hit me like cold water. Raising agent. I’d forgotten the baking powder.

“It’s a funny story,” Greg said. “It’s an anecdote for your post.”

“It’s a disaster,” I wailed. “I’ll never know happiness again.”

In the first madness of denial, I even considered the logistics of trying to mix baking powder into each pocket of marble. Reluctantly, with Greg’s love and support, I realised that there was nothing for it: either remix the batter with baking powder and lose the marble, or plough on in the vague hope that somehow, some way, it might be okay. I chose the latter option. It was not okay.

The heartbreak of getting it out of the oven, seeing that gorgeous marble on top, and knowing that only angst and despair lay beneath it. We tipped it out of the tin, we cut the loaf. Sure enough, it was a flat, gooey mess. In fact, it had gone so wrong, and I was so tired that evening, that I wouldn’t be surprised if I had missed something else out, too. Like, the banana or the egg or the flour or the sugar or any one of the core ingredients, to be honest. It was really quite the disaster.

Deceptively pretty – the baking-powder-less banana bread

There was nothing for it but to mourn the first attempt and begin again. Greg’s parents were not going to eat a banana flatbread with approximately the density of a supermassive black hole.

Luckily, when made with all the necessary ingredients, this banana bread is top notch. It gives a good marble, and gluten-free bakes always work well if you introduce a little more moisture via a darker sugar or wetter ingredients such as carrot or banana, so this bread plays to all those strengths. ☺️

Gluten-free and dairy-free marbled banana bread

Note: Just to say that the failed banana bread did have a happy ending of sorts. I crumbled it up, mixed it with some buttercream and made cake pop truffle balls. They took about zero effort, but received surprisingly rave reviews from family members (see below from Ed, my brother, who is notoriously hard to please with home-baked treats):

Gluten-free marbled banana bread

Gluten-free and dairy-free marbled banana bread


  • 2 large or 3 medium ripe bananas, mashed
  • 1 large free-range egg, at room temperature
  • 120 ml vegetable or sunflower oil
  • 150g light muscovado sugar
  • 1 tsp vanilla extract
  • 140g plain gluten-free flour (with no xantham gum!)
  • 1 tsp baking powder
  • pinch of salt
  • 25g cocoa

Notes: If you use xantham gum, then the marble effect will not work – the colours will blend while they bake and you’ll have a perfectly nice chocolate banana bread, but no marble. Make sure your flour blend doesn’t contain it!

Gluten-free and dairy-free marbled banana bread


  1. Preheat your oven to 175 C and grease & line a 2lb loaf tin.
  2. In a large mixing bowl, whisk together the mashed bananas, egg, sugar, oil and vanilla.
  3. Sift in the gluten-free flour, baking powder and salt (not the cocoa!), and mix until combined. Divide the mixture evenly between two bowls. Add the cocoa to one bowl and fold it in. If the mixture seems heavy, add a tablespoon of milk (or a dairy-free alternative).
  4. Using alternate tablespoonfuls of the vanilla and chocolate mixtures, fill the tin until you’ve used up the mixture in both bowls. Using a skewer, gently marble the top of the cake to create a pretty pattern of swirls.
  5. Pop the cake in the oven and bake for 40–45 minutes, or until a skewer comes out clean. Leave the cake to cool in the tin for five minutes or so, and then carefully turn it out to cool fully on a wire rack.

Gluten-free banana marble cake

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