Banana Cake with Chocolate Frosting
Super moist banana cake topped with a chocolate sour cream frosting.
Servings: 9 squares
Calories: 455kcal
Equipment
- 1 8x8 baking pan
Ingredients
Banana Cake
- ½ cup unsalted butter
- 1 cup bananas mashed
- ½ cup light brown sugar
- ¼ cup white sugar
- 2 teaspoons vanilla extract
- 2 large eggs room temperature
- ¼ cup buttermilk room temperature
- 1 teaspoon baking soda
- ½ teaspoon baking powder
- ½ teaspoon ground cinnamon
- ½ teaspoon kosher salt
- 1 ¾ cup all purpose flour
Chocolate Frosting
- 3 oz dark chocolate chopped
- ½ cup unsalted butter room temperature
- 1 cup confectioners' sugar
- ½ cup cocoa powder
- ¼ cup sour cream room temperature
Instructions
Banana Cake
- Preheat the oven to 350°Fahrenheit/175°Celsius. Grease and line an 8x8 baking pan with parchment paper and set aside. Make sure the parchment is overhanging so you can easily lift the cake out.
- Melt the butter in a large microwave safe bowl. Whisk in the mashed banana.½ cup unsalted butter, 1 cup bananas
- Add the sugar and light brown sugar and whisk into the banana mixture for 1 minute.¼ cup white sugar, ½ cup light brown sugar
- Add in the two eggs, buttermilk and vanilla extract, whisking until almost smooth - it will be a little bit lumpy because of the banana which is fine!2 large eggs, ¼ cup buttermilk, 2 teaspoons vanilla extract
- Pour in the dry ingredients - the flour, baking soda, baking powder, salt and ground cinnamon. Use a rubber spatula to fold everything together until there are no more streaks of flour.1 teaspoon baking soda, ½ teaspoon baking powder, ½ teaspoon kosher salt, 1 ¾ cup all purpose flour, ½ teaspoon ground cinnamon
- Pour the cake batter into the prepared pan. Bake for 30-35 minutes. A toothpick inserted should come out with little to no crumbs. Let it cool in the pan for 20 minutes before gently lifting out and letting it cool completely on a wire cooling rack.
Chocolate Frosting
- Melt the chocolate in a microwave safe bowl in 15 second increments, stirring every 15 seconds so it doesn't burn. Once melted, set aside to cool.3 oz dark chocolate
- In a stand mixer fitted with the paddle attachment, or in a large bowl with a handheld mixer, beat the butter and confectioners' sugar together on low speed until it comes together. Turn the speed to high and beat for 2 minutes until light and fluffy.½ cup unsalted butter, 1 cup confectioners' sugar
- Pour in the cocoa powder and beat on low until just combined, then increase the speed to medium and beat for another 2 minutes.½ cup cocoa powder
- Pour in the melted chocolate and sour cream and mix once more. You may need to scrape down the sides of the bowl so everything is getting combined!¼ cup sour cream
- Spread this chocolate frosting on top of the banana cake.
Notes
My recipes have been developed and tested in metric grams. I highly recommend using a weighing scale and measuring out your ingredients the metric way.
Butter: I use European style butter, like Kerry Gold, in my recipes. This will make your finished bake much creamier and richer.
Salt: If you don’t have kosher salt, halve the amount of salt called for in the recipe. 1 teaspoon kosher salt = ½ teaspoon fine salt. Please note I am using Diamond Crystal Kosher Salt and not Morton Salt, which is a coarse kosher salt. Coarse kosher salt is much too salty for this recipe.
Buttermilk: If you don’t have buttermilk, replace it with an equal amount of sour cream or full fat yoghurt. You can also make your own buttermilk, for every cup of buttermilk add 1 tablespoon of lemon juice to 1 cup of milk and let sit for 5 minutes.
Cocoa Powder: I used unsweetened cocoa powder here but you could use dutch-processed if that is what you have on hand.
Make Ahead: you can make the frosting a day ahead. Once you've made it, place clingfilm to the top of the frosting (so it doesn't form a crust). Place in the fridge. The next day, take out the frosting an hour before using it so it can come to room temperature. If it's still to hard, microwave the frosting 5-10 seconds.
Storage: Keep tightly wrapped in the fridge or in an airtight container for up to 4 days. Let it come to room temperature before eating. Nutrition
Calories: 455kcal | Carbohydrates: 62g | Protein: 6g | Fat: 28g | Saturated Fat: 17g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 8g | Trans Fat: 1g | Cholesterol: 100mg | Sodium: 309mg | Potassium: 282mg | Fiber: 4g | Sugar: 23g | Vitamin A: 756IU | Vitamin C: 2mg | Calcium: 68mg | Iron: 3mg
