Banana Sponge Cake with Chocolate Buttercream

The most soft and spongy banana sponge cake with a delicious dark chocolate buttercream. This simple banana cake is so easy to make and taste absolutely delicious.

Banana Sponge:
bananas, very ripe (180 g)
all-purpose flour, unbleached (175 g)
½ tsp. baking powder
¾ tsp. baking soda
½ tsp. sea salt
full-fat milk (75 g)
½ tsp. pure vanilla extract
butter, room temperature (60 g)
granulated sugar (125 g)
2 eggs

Chocolate Buttercream:
semi-sweet dark chocolate (50 g)
heavy cream (40 g)
butter, room temperature (50 g)
confectioners' sugar (90 g)
½ tsp. pure vanilla extract

Preheat the oven to 340°F (170°C/150°C fan, Gas Mark 3) and prepare a 20x20 cm baking pan with parchment paper.

Stir all-purpose flour, baking soda, baking powder and salt together in a bowl.

Mash the bananas and set it aside. Mix together milk and vanilla extract and set it aside.

Add the butter and granulated sugar in a bowl and whisk it together with a strand mixer or with an electric hand-mixer. Whisk on high speed, for 2-3 minute so it becomes light and airy

At low speed, add the eggs one at a time until they are incorporated into the batter.

Continue on a low speed, and add ⅓ of the flour mixture and mix it in. Then add the mashed banana and mix it in. Add another ⅓ of the flour mixture and mix it in. Add the milk/vanilla and mix it in. Finally add the last ⅓ of the flour mixture and mix until just combined. Be careful to not over mix.

Use a spatula, and give the batter a final mix, making sure everything has been combined.
Add the cake batter into the prepared baking tin and bake them for 28-30 minutes or until a cake tester comes out clean.

Let the cake cool on a cooling rack. After 5-10 minutes, gently remove the cake from the cake tins and let it cool down completely.

For the Chocolate Buttercream:
Melt the dark chocolate and heavy cream together over a bain-marie or in the microwave. Let it cool down to room temperature (it’s important that it’s not too hot).

Sift the powdered sugar.

Start by creaming the butter, with hand mixer or in your stand mixer, for 4 minutes on medium/high speed.

Scrape down the sides of the bowl and add the vanilla extract and the sifted powdered sugar and mix it together with the butter on low speed. Then, scrape down the sides of the bowl, and mix for 2 minutes on low/medium speed.

Finally add the room temperature melted dark chocolate and mix it in until incorporated. Scrape down the sides of the bowl and give it another mix to make sure it’s fully incorporated.

Tip: If the buttercream feels too soft, place in the fridge for 5-10 minutes. Then give it a good mix again before adding it on the cake.

Add the chocolate buttercream on top the banana sponge cake and with an offset spatula, even it out.

Makes 9 servings.

Nutritional information:
Calories: 336kcal, Carbohydrates: 47g, Protein: 4g, Fat: 15g, Saturated Fat: 9g, Polyunsaturated Fat: 1g, Monounsaturated Fat: 4g, Trans Fat: 0.4g, Cholesterol: 69mg, Sodium: 319mg, Potassium: 158mg, Fiber: 1g, Sugar: 29g, Vitamin A: 453IU, Vitamin C: 2mg, Calcium: 29mg, Iron: 1mg