Marbled Banana Loaf Cake

Sometimes I don’t buy bananas and my family will ask for them. Sometimes I buy bananas and no one touches them. You feel me? If the bananas are ripening fast and no one is touching – use them up for this cake!

With young kids, I love making loaf cakes. My loaf pan has been getting alot of action these past couple of years. I get to freeze them into quarters and thaw them to slice up as and when needed.

Also with young kids, I’ve learnt the freezer is your friend. They might not be able to finish all that you’ve baked/made, so freeze the rest depending on type of food and thaw overnight if possible, when wanting to consume.

Also with young kids, I get them to help out in the kitchen when I’m not easily annoyed and with this recipe they get to swirl the batters at the very end and my kids thought it was fun.

BUT to even consider this recipe, be sure you have the star ingredients, ripe bananas, baking chocolate and sour cream. 

The sour cream is not pictured above but you will need it. 

With this cake, two batters are created. One plain and one chocolate and they get married in the end.

First you will create the plain batter by mixing the butter and sugar till well combined. Then in goes the eggs and the flour mix (flour + baking soda+ salt). At the end, we will add in the sour cream, bananas and vanilla essence.

For the chocolate batter, we will melt the baking chocolate and add some cocoa powder to it. Then we will add in one cup of the plain batter – and there you have it – the chocolate batter. Add them into the loaf pan and then the swirling action to seal the deal.

Now comes the swirling. Don’t let the kids go overboard – up and down 5 times should do.

I got this recipe from this site. I’ve tried maybe 3 of the author’s recipes and loved them all. Original post here.

Did you try this recipe?

Please do let me know if you've tried it, by leaving a comment or tagging me on IG @thesuddencook.

Marbled Banana Cake

The cake is not only yums but it's also fun to make with your kids cause they get to do something fun at the end!


  • Loaf Pan
  • 2 bowls
  • Electric Mixer


  • 220 g Plain Flour
  • 113 g unsalted butter sometimes I use salted it's fine. Make sure at room temp and has softened.
  • 200 g sugar
  • 2 eggs
  • 120 g sour cream
  • 3 mashed very ripe bananas The mashed banana should weigh about 240g
  • 2 tsp cocoa powder Use a good quality one
  • 3/4 tsp baking soda
  • 3/4 tsp salt
  • 1 tsp vanilla essence
  • 80 g baking chocolate At room temp.


  • Preheat your oven to 180C. Line your loaf pan with baking paper.You may also choose to grease your pan first.
  • In a medium bowl, whisk together the flour, baking soda + salt.
  • In a separate bowl, use an electric mixer and mix butter and sugar for about 2 minutes. Add eggs one at a time and continue to beat well. Add in flour and mix on low speed till combined.Scrap down sides of bowl and ensure all is incorporated. Add the mashed bananas + sour cream + vanilla essence and beat till all mixed well.
  • Now to melt the chocolate. You may use the microwave. Place the chocolate pieces in a microwavable bowl and microwave for 20 seconds. Check and see if it needs to go further add another 10 seconds. When it's about 80% melted, remove and keep stiring it will go on to melt completely. Add cocoa powder and stir well. Now add one cup of the plain batter into this mix.
  • So now you will have two batters - chocolate and plain. Add the batters alternatively into the loaf pan. Swirl the batters around with a knife or chopstick 5 times. (The fun part for the kids!).
  • Bake for 50 minutes - 1 hour. Please check as every oven is different. For me this loaf cake was done after 50 mins. Once done, remove loaf pan and let cake cool in pan for a while before removing. Once removed, let it cool completely before slicing.


My Top Tips are:
  1. The sour cream is a must. Don't skip it as this results in a moist cake.
  2. Butter, eggs, sour cream and chocolate should be removed from fridge at least 20 mins prior to starting the cake.
  3. Don't go crazy with the swirling as the cake may not turn out instragram worthy after that!
Good luck!
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3 years ago

Very exciting ! Will try with the kids for sure