Banana Cake with Chocolate Frosting

Name: Banana Cake with Chocolate Frosting Recipe
Prep time: 20 min
Cook time: 25 min
Total time: 45 min
Ingredients: ½ cup unsalted butter; 1 ½ cups all-purpose flour; ¼ cup granulated sugar; ¾ teaspoon baking soda; 1 teaspoon salt; 1 cup mashed bananas (2 to 3 very ripe bananas); ¼ cup full-fat sour cream; 2 tablespoons dark brown sugar (packed); 2 large eggs (room temperature); 1 teaspoon vanilla extract; 8 ounces dark chocolate baking bar (not chocolate chips if you can avoid it); 1 cup unsalted butter (room temperature); 2 tablespoons heavy cream; 1 teaspoon vanilla extract; 3 cups powdered sugar; 1 tablespoon instant coffee granules (+ 3 teaspoons hot water optional)

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Banana and chocolate are such a great flavor combination! This moist banana cake with chocolate frosting is filled to the brim with banana flavor and topped with a simple frosting. It's the perfect way to use up those overripe bananas with a great recipe that everyone is sure to love!

Looking for more banana recipes? Try Banana Cake with Salted Caramel Frosting, Sour Cream Banana Bread, and Banana Chocolate Chip Muffins.

Snack sized pieces of banana cake with chocolate frosting.

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Why you’ll love this recipe

This cake recipe makes a simple, one layer banana cake with a thick layer of chocolate frosting. It's perfect for snacking or dessert after family dinner
My Banana Cake with Salted Caramel Frosting is a popular recipe, so I wanted to serve up another popular flavor variation for chocolate lovers
Banana recipes like this one are great for using up overripe bananas! Want to bake but you don't have ripe bananas? I have a 15-minute trick for getting your unripe bananas ready for baking!

Banana sitting in front of a banana cake with chocolate frosting on top.

Ingredients & substitutions

Butter: For baking recipes, stick with unsalted butter unless salted butter is specific in the recipe. This allows you to control the level of salt in your baking. There's no need to bring the butter to room temperature, as it will be melted and made into brown butter. Browning butter caramelizes the milk solids in butter, adding a layer of subtly nutty flavor that you wouldn't otherwise achieve with plain melted butter. Get tips for how to achieve the perfect browned butter
All-purpose flour
Granulated sugar
Baking soda
Salt
Mashed Bananas: Overripe brown bananas work best here, as they'll have the best flavor and sweetness for this cake. Depending on the size of your bananas, you'll need about 2 to 3 very ripe bananas. If you only have green bananas, yellow bananas, follow this tip for ripening bananas in the oven for baking. Use it for all your banana desserts!
Sour cream: this ingredient helps keep this banana cake super moist and adds a bit of richness. Plain Greek yogurt may be substituted
Dark brown sugar: Only a small amount of brown sugar is needed here. I recommend using dark brown sugar, as it helps bring out a caramely flavor in the cake. However, light brown sugar may be substituted
Large eggs: Be sure to remove the eggs from the fridge at least 30 minutes prior to baking to allow them to reach room temperature. Cold eggs will not incorporate well into the other ingredients, so room temperature eggs are essential
Vanilla extract

Banana cake sitting on parchment paper in an 8x8 baking pan.

For the frosting, you'll need:

Chocolate: I highly recommend using real dark chocolate in the form of a chocolate baking bar, such as Ghiradelli, Baker's or Scharffen Berger, rather than chocolate chips if you can avoid it. Chocolate chips tend to include stabilizers that help them retain their shape when heated or baked. In this case, we want chocolate that melts well to help achieve an ultra smooth consistency. The dark chocolate may be substituted for milk chocolate to make milk chocolate buttercream frosting
Unsalted butter: An important step in achieving a creamy texture for your frosting is to ensure that you use room temperature butter. I recommend removing it from the fridge at least an hour or more before you being making the frosting. You want butter that is soft, but not melted. I like to leave my butter on the counter overnight. This ensures you will not have cold butter, which tends to leave chunks of butter throughout the frosting.
Heavy cream or heavy whipping cream: If you only have milk, that may also be used
Vanilla extract
Powdered sugar: Otherwise known as confectioners' sugar. If your sugar is particularly lumpy, you may want to sift it to help create smoother frosting without clumps of sugar in it
Instant coffee granules: Don't worry, your frosting will not taste like coffee at all! The instant coffee gets mixed with a bit of hot water and added to the frosting. Coffee enhances the flavor of chocolate. If you are a fan of dark chocolate, this is a must! If you prefer not to include coffee, it can be easily omitted

A small glass jar of dark chocolate buttercream frosting sitting in front of unfrosted cupcakes.

How To Make Banana Cake with Chocolate Frosting

Step 1

Preheat the oven to 350 degrees F. Line a square pan with parchment paper letting the two long ends hang over the edges by at least 2 inches. Butter the top of the parchment and set aside.

Melt the butter in a small saucepan, cooking and stirring until the butter is just browned (be careful not to cook too long or it’ll burn). See this post for How to Brown Butter for more tips and tricks. Set aside to cool slightly before adding to the cake batter.

Step 2

In a large bowl, whisk together flour, granulated sugar, baking soda and salt. In s separate medium bowl, whisk together the bananas, sour cream, brown sugar, eggs and vanilla. Combine the wet ingredients with the dry ingredients. Once the flour mixture has been almost fully incorporated with the banana mixture (you should still see a few dry spots of flour) whisk in the browned butter. Scrape the cake batter into the prepared baking pan and smooth the top with an offset spatula or butter knife.

Step 3

Bake until the top springs back when lightly pressed in the center, and a toothpick inserted in the center comes out clean, about 25 minutes. Lift out of the pan and place on a wire rack to cool

Step 4

Meanwhile, prepare the Chocolate Frosting. Chop the chocolate and place it in a heatproof bowl over a pan set over simmering water (be sure the bowl is not touching the water so your chocolate does not scorch). Stir the chocolate until it's just melted and set aside until cooled to room temperature.

In the bowl of a stand mixer fitted with the paddle attachment or with an electric mixer or hand mixer, cream butter on medium-high speed until light yellow and fluffy, about 3 minutes.

Add the heavy cream and vanilla and continue beating for 3 minutes. Turn the mixer to low, gradually add the powdered sugar, then beat at medium speed, scraping down the bowl as necessary, until smooth and creamy.

In a separate bowl, dissolve the coffee in 2 teaspoons of the hottest tap water. With the mixer on low speed, add the chopped chocolate and dissolved coffee to the butter/sugar mixture and beat until blended and smooth.

Step 5

Once the cake is completely cooled, frost the cake (you may not use all the frosting). Slice into 16 squares and serve

Chocolate frosting covering a banana cake in an 8x8 baking pan.

Pro tips

This easy cake recipe is best made using overripe bananas. The riper a banana is, the sweeter it is. For tips on ripening bananas for baking, check out this post.
To make this recipe into a banana layer cake, double the recipe. Use two 8-inch round cake pans and divide the batter equally between the pans. Bake until the center of the cake is no longer wet looking ot a toothpick inserted into the center of the cake layers comes out with just a few crumbs on it. Cool the cakes completely before filling and frosting with the chocolate buttercream.
If preparing this cake in advance, wrap the cake while it's still warm tightly in plastic wrap and leave at room temperature up to 3 days. Wrapping the cake while it's warm will help keep it moist

Like this recipe? Follow me on Pinterest for lots more recipes just like this one! And don’t forget to pin this recipe for later by clicking on one of the images below the recipe. Or, click on any of the images in this post to save to Pinterest.

FAQs

What is the difference between banana loaf and banana cake?

Banana Cake tends to have frosting or icing whereas banana bread does not. Banana cake is also lighter in texture than banana bread which can be a bit heartier.

How many bananas do you need to make banana cake?

For this recipe, you'll need about 2 to 3 medium bananas. It's best to follow the recipe for volume or weight of banana rather than number of bananas, since bananas can vary greatly in size. For this cake, you'll need 1 cup of mashed banana.

How to make banana chocolate chip cake?

To make this recipe into Banana Chocolate Chip Cake, simply add ½ cup of semi-sweet chocolate chips to the banana cake batter at the very end, before pouring the batter into the prepared pan.

Can I use this recipe to make a two-tier banana cake with chocolate frosting?

Yes! To make this into a layer cake, double the recipe for the cake batter and for the frosting. Use two 8-inch round pans and divide the batter equally between the pans. Bake until the center of the cake is no longer wet looking ot a toothpick inserted into the center of the cake layers comes out with just a few crumbs on it. Cool the cakes completely before filling and frosting with the chocolate buttercream.

FOR ALL MY FAVORITE BAKING TOOLS INCLUDING THOSE USED TO MAKE THIS RECIPE, CHECK OUT MY BAKING RESOURCES PAGE!

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