Banana Cake with Chocolate Frosting

💕 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!

🧾 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

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

✨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 5

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

👩‍🍳 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