Chocolate Marble Banana Bread

I love a good banana bread, and this one is so special with the chocolate swirl throughout. It’s actually much easier to make than it looks!

I am an absolute banana bread lover. I will buy very ripe bananas on purpose because I want to buy banana bread (or banana muffins) every week, otherwise I feel like I’m missing something 😂

Here, we’re adding a wonderful chocolate swirl throughout the bread – kind of like a marble pound cake with the added benefit of delicious banana flavor!

Ingredients you’ll need

Here is a visual overview of the ingredients in the recipe. Scroll down to the printable recipe card at the bottom of this post for quantities!

Ingredient notes

• Cocoa powder and milk: I always make the chocolate swirl with cocoa powder and a little milk because it’s easy and doesn’t require an extra dish. For a more chocolate-y swirl, melt ¼ cup chocolate chips and stir them into the batter in place of the cocoa powder and milk.
• Bananas: The bananas need to be overripe for the bread to work and to turn out flavorful and sweet.
• Oil: Feel free to use melted butter in place of the oil. I recommend a neutral-tasting cooking oil if you’re going with oil. I used canola.

How to make banana bread with a chocolate swirl

1. Start by combining the dry ingredients in a large mixing bowl.

2. Next, mash the bananas in a separate bowl or measuring jug.

3. Add the remaining wet ingredients to the mashed bananas. Then, mix the wet ingredients until fully combined.

4. Now, pour the wet ingredients into the bowl with the dry ingredients. Fold them together using a rubber spatula just to combine. Do not overmix the batter, or your banana bread will come out dense and gummy!

5. Add ⅔ of the batter to a lined loaf pan. Add the cocoa power and milk (OR melted chocolate chips) to the remaining batter in the bowl.

6. Pour the chocolate batter evenly over the plain batter in the pan. Using a fork, swirl the two together (please check out the video for my technique! It is so quick and simple and yields the most beautiful swirl!).

Then just bake the bread, allow it to cool a little and then enjoy warm!

Recipe tips

• Do not overmix the batter! It is very important to only combine the wet and the dry ingredients JUST until they’re combined. Lumps are perfectly fine. Do NOT use a whisk to combine the batter! Always use a rubber spatula or a wooden spoon.
• Don’t over-marble and don’t under-marble. Marbling is best done with a fork spiraling through the batter, swirling darkness and light together. Make sure to check out my recipe video below to see my technique! But really, most of it is just a surprise once you finally slice into your bread 😉
• Do not overbake the bread. The banana keeps the bread nice and moist, but overbaked banana bread is still dry.

PS If you try this recipe, please leave a review in the comment section and add a star rating in the recipe card – I appreciate your feedback! Follow along on Pinterest, Facebook or Instagram.

Recipe first published on 08/22/2014. Updated with better recipe, new photos, video and text on 02/27/2021.

More banana bread recipes

You can also browse all of my quick bread recipes here, browse all of my banana recipes here, or browse all of my baking recipes here!