The perfect combination of sweet bananas and lots of chocolate! This Chocolate Banana Cake bakes up moist and tender and it’s topped with a creamy chocolate frosting. Made in a 9×9 square pan, this cake is the perfect size for snacking or small celebrations.
We’re always looking for ways to use up overripe bananas and apparently you are, too. Our Easy Banana Bread, Banana Nut Muffins, and Banana Bundt Cake are three of our most popular recipes. If you enjoy the marriage of chocolate and bananas, this is the cake for you!

Jump to:
Why you’ll love this recipe
Flavor: Chocolate and bananas!
Texture: A soft and moist cake topped with a super creamy frosting.
Size: Not too big and not too small, this 9×9 cake is perfect for snacking or small celebrations.
Use up extra bananas: This is one of the most delicious way to use up overripe bananas. You’ll need about 2 medium-sized bananas for this recipe.
Recipe overview
Combine flour, cocoa powder, baking soda, and salt. Set aside.

Using a hand mixer or stand mixer, beat butter, granulated sugar, and brown sugar. Add mashed banana, eggs, and vanilla.

Add the dry ingredients to the wet ingredients, beating until combined. Spread the batter into a greased 9×9 pan. Bake.

Once the cake has baked and cooled, prepare the frosting. Beat butter until smooth. Add powdered sugar, cocoa powder, milk, and vanilla extract. Spread the frosting on top of the cake. Top of shaved chocolate, if desired.

Tips: baking with bananas
It’s important that you use overripe bananas for this recipe. The skin of the banans should have brown speckles or even be turning dark brownish-black. This ensures that the bananas mash smoothly and are extra sweet.
You will need 2-3 bananas to make 1 cup.
Mash the bananas using a fork or potato masher.
I mash the bananas on a paper plate then fold the plate to slide the mashed banana into the measuring cup.
Topping options
This cake is topped with a generous amount of chocolate frosting. If you’d like less frosting you can cut the frosting recipe in half.
Top the frosted cake with chocolate shavings, chocolate curls, chocolate sprinkles, or sliced banana. Wait to add the banana until you’re serving it.

Serving and storage
This cake is best served at room temperature.
Store tightly covered in the refrigerator for up to 3 days. Bring to room temperature before serving.
Recipe

Chocolate Banana Cake
Ingredients
Cake:
- 1¼ cups all purpose flour
- ½ cup unsweetened cocoa powder
- ¾ teaspoon baking powder
- ½ teaspoon baking soda
- ¼ teaspoon salt
- ½ cup unsalted butter, softened
- ⅓ cup granulted sugar
- ½ cup light brown sugar, packed
- 1 cup mashed overripe banana
- 2 large eggs, room temperature
- 1 teaspoon pure vanilla extract
- ⅓ cup milk or buttermilk
Frosting (see note):
- 1 cup unsalted butter, softened
- 3½ cups powdered sugar
- ½ cup unsweetened cocoa powder
- ¼ cup milk
- 1 teaspoon pure vanilla extract
- chocolate shavings and/or sliced banana, optional topping
Instructions
Cake:
- Preheat oven to 350°F with a rack in the center of the oven,
- Combine flour, cocoa, baking powder, baking soda, and salt. Set aside.
- Using a hand mixer or stand mixer fitted with the paddle attachment, beat butter, granulated sugar, and brown sugar until creamy and combined. Add mashed banana, eggs, and vanilla beating until well combined and scraping the sides and bottom of the bowl as necessary. Add half of the flour mixture, beating until combined, add milk then remaining flour beating well between each addition and scarping the sides and bottom of the bowl and beater.
- Transfer the batter into a greased 9×9 square baking pan and spread into an even layer. Bake for 23-27 minutes, until a toothpick inserted into the center comes out clean. Place the pan on a wire rack to cool completely.
Frosting:
- Using a hand mixer or stand mixer fitted with the paddle attachment, beat butter until smooth. Add half the powdered sugar and all the cocoa powder. Beat in vanilla and half the milk followed by remaining powdered sugar. Add as much more milk as you need to get your desired consistency. Turn speed up to medium-high and beat for 30 seconds. Spread the frosting on top of the cooled cake.
Notes
Nutrition
Nutritional Information is an estimate based on third-party calculations and may vary based on products used and serving sizes.
Liz says
I have so many bananas that I needed to use so this recipe came at the perfect time! I love the chocolate + banana combo.
Jenn says
This chocolate banana cake is perfect for my spotty bananas! It looks and sounds amazing — thank you for the recipe! xoxo
Esther says
Hi:)
I used flora margarine instead and only brown sugar and it turned out AMAZING:-)..
I also added a chocolate chips.
This recipe is a keeper!!!!
Allison says
Perfect! I’m glad you enjoyed it. 🙂