Why You’ll Adore This Easy Banana Cake Recipe!

This isn’t just another banana cake; it’s a culinary experience designed for maximum flavor with minimal fuss. Here’s why this recipe will quickly become a cherished favorite in your baking repertoire:

• This banana cake is essentially a more decadent, cake-like version of your favorite banana bread! It’s a single-layer sheet cake generously crowned with a thick, luxurious layer of creamy chocolate frosting, offering all the comforting flavors of banana bread in a more elegant, dessert-ready format.
• It’s the ultimate solution for those times you have a few too many perfectly overripe bananas sitting on your counter. Instead of letting them go to waste, transform them into a delightfully sweet and moist treat. Overripe bananas are key here, lending natural sweetness and unparalleled moisture to the cake.
• The entire cake batter is prepared in just one bowl, and you won’t need an electric mixer. This means less cleanup and a super straightforward process, making it perfect for novice bakers or anyone looking for a quick and easy baking project.
• The rich and flavorful chocolate sour cream frosting can be made in advance. Simply store it in the refrigerator, and let it come to room temperature before you’re ready to spread it over your cooled banana cake, saving you valuable time on baking day.
• This cake is incredibly moist and tender, thanks to the combination of ripe bananas and buttermilk. Every bite is soft, flavorful, and truly satisfying.
• It’s a fantastic crowd-pleaser! The classic combination of banana and chocolate appeals to almost everyone, making it ideal for potlucks, family gatherings, or a simple dessert after dinner.

Essential Ingredients for Your Perfect Banana Cake

Creating this wonderfully moist banana cake with its decadent chocolate frosting requires a few key ingredients. Quality matters here, so choose fresh ingredients for the best results. Here’s a breakdown of what you’ll need and why each component is important:

• Overripe Bananas: This is the star of our show! Make absolutely sure to use bananas that are deeply speckled with dark spots, or even entirely black. These bananas are significantly sweeter and much easier to mash, imparting a robust banana flavor and incredible moisture to your cake. Green or slightly yellow bananas will not yield the same delicious results. For roughly 1 cup of mashed bananas, you’ll typically need about 2-3 medium-sized bananas.
• All-Purpose Flour: We’ve specifically developed and tested this recipe using standard all-purpose flour. It provides the perfect structure and tender crumb for this cake. While other flours might work, results may vary, so sticking to all-purpose is recommended.
• Buttermilk: This ingredient is crucial for keeping our banana cake exceptionally moist and tender. Its acidity reacts with the baking soda, contributing to the cake’s light and fluffy texture. If you don’t have buttermilk on hand, don’t fret! You can easily substitute it with an equal amount of sour cream or plain full-fat yogurt. Alternatively, you can make a quick homemade buttermilk substitute by mixing 1 cup of whole milk with 1 tablespoon of lemon juice or white vinegar and letting it sit for 5-10 minutes until it slightly curdles.
• Unsalted Butter: You’ll need softened unsalted butter for both the cake batter and the luscious frosting. Using unsalted butter allows you to control the overall saltiness of your bake. For the cake, melted butter is used, but ensure it’s cooled before combining with other wet ingredients. For the frosting, room temperature softened butter is essential for achieving that light, fluffy consistency.
• Granulated & Light Brown Sugar: The combination of both sugars adds depth of flavor and moisture. Granulated sugar provides sweetness, while light brown sugar adds a subtle caramel note and extra moisture due to its molasses content.
• Eggs: Large eggs, preferably at room temperature, help bind the ingredients and add richness and structure to the cake. Room temperature eggs emulsify better with other ingredients, leading to a smoother batter.
• Vanilla Extract: A splash of good quality vanilla extract enhances all the other flavors, bringing warmth and aromatic complexity to both the cake and the frosting.
• Baking Soda & Baking Powder: These leavening agents work together to give the cake its lift and tender crumb. The baking soda specifically reacts with the acidic buttermilk (or bananas) for an extra boost.
• Ground Cinnamon: I personally love a slightly spiced banana cake, as cinnamon beautifully complements the banana flavor. If you’re not a fan, you can certainly leave it out, or substitute with a pinch of nutmeg or allspice for a different warm spice profile.
• Kosher Salt: A touch of salt is vital in baking to balance the sweetness and enhance the overall flavors. We recommend kosher salt; if using fine table salt, remember to halve the amount as it’s more concentrated.
• Dark Chocolate (for frosting): Opt for good quality dark chocolate (around 60-70% cocoa solids) for the richest chocolate frosting flavor. Chopping it finely will help it melt smoothly and evenly.
• Confectioners’ Sugar (Powdered Sugar): This fine sugar is essential for achieving a smooth, lump-free texture in your chocolate frosting.
• Unsweetened Cocoa Powder: Used in the frosting, unsweetened cocoa powder provides a deep, intense chocolate flavor. While we use unsweetened, Dutch-processed cocoa powder can be used if that’s what you have, though it might result in a slightly darker color and milder chocolate flavor.
• Sour Cream (for frosting): Just like buttermilk in the cake, sour cream adds an incredible tang, richness, and creaminess to the chocolate frosting, preventing it from being overly sweet and giving it a wonderfully smooth mouthfeel. Ensure it’s at room temperature for optimal mixing.

Easy Step-by-Step Guide to Baking Your Banana Cake

Follow these detailed instructions to create a perfectly moist banana cake with irresistible chocolate frosting. We’ve broken down each step to ensure your baking experience is smooth and successful.

Step 1: Prepare Your Oven and Pan. Begin by preheating your oven to 350°Fahrenheit (175°Celsius). Lightly grease an 8×8 inch (20×20 cm) baking pan and line it with parchment paper, making sure the parchment overhangs on two sides. This overhang creates “handles” that will make it incredibly easy to lift your cooled cake out of the pan later. Set the prepared pan aside.

Step 2: Combine Wet Ingredients. In a large, microwave-safe mixing bowl, melt your unsalted butter. Once melted, allow it to cool slightly for a few minutes. Then, add the mashed overripe bananas to the cooled melted butter. Whisk these two ingredients together until well combined. The bananas should be mashed until mostly smooth, but a few small lumps are perfectly fine and add to the texture.

Step 3: Add Sugars, Eggs, and Liquids. Pour in both the white granulated sugar and the light brown sugar into the banana-butter mixture. Whisk vigorously for about 1 minute until the sugars are mostly dissolved and the mixture is well integrated. Next, crack in the two large eggs, add the buttermilk (or your chosen substitute), and the vanilla extract. Whisk again until everything is just combined. As mentioned, some small lumps from the banana are normal and won’t affect the final cake texture.

Step 4: Incorporate Dry Ingredients. Sift or gently fold in all of your dry ingredients: the all-purpose flour, baking powder, baking soda, kosher salt, and ground cinnamon. Using a rubber spatula, carefully fold the dry ingredients into the wet mixture until there are no visible streaks or pockets of flour remaining. Be careful not to overmix the batter; overmixing can lead to a tough cake.

Step 5: Bake the Cake. Pour the banana cake batter evenly into your prepared 8×8 baking pan. Transfer it to the preheated oven and bake for approximately 30-35 minutes. To check for doneness, insert a wooden toothpick into the center of the cake; it should come out clean or with only a few moist crumbs attached. Avoid overbaking, as this can lead to a dry cake. Once baked, remove the pan from the oven and let the cake cool in the pan for about 20 minutes before using the parchment paper overhang to gently lift it out. Transfer the cake to a wire cooling rack to cool completely. This is crucial before frosting.

Step 6: Prepare the Chocolate Frosting Base. While your cake is cooling, start on the frosting. In the bowl of a stand mixer fitted with the paddle attachment, or using a large bowl and a handheld mixer, beat the softened unsalted butter and confectioners’ sugar together on low speed until they are just combined and no dry sugar remains. Then, increase the speed to medium-high and beat for a full 2 minutes until the mixture is light, fluffy, and noticeably pale.

Step 7: Finish the Frosting. Add the unsweetened cocoa powder to the butter and sugar mixture. Beat on low speed until the cocoa powder is fully incorporated. Then, increase the speed to medium and beat for another 2 minutes, ensuring the frosting is smooth and well-aerated. Finally, pour in the *cooled* melted dark chocolate and the room temperature sour cream. Mix once more on medium speed until everything is thoroughly combined and smooth. You may need to stop and scrape down the sides of the bowl with your spatula to ensure all ingredients are fully integrated. Once the cake is completely cool, generously spread this decadent chocolate sour cream frosting evenly over the top.

Expert Baking Tips & Tricks for Success

Achieving a perfect banana cake with a flawless frosting isn’t difficult, especially with these helpful tips and tricks:

• Accurate Ingredient Measurement – Use a Weighing Scale: For consistent and professional baking results, I cannot stress enough the importance of using a digital kitchen scale. Measuring ingredients in grams (the metric way) is the most accurate method and makes a huge difference in the outcome of your baked goods. If you don’t have a scale, volumetric measurements (cups) can be less precise.
• Proper Flour Measurement (If Using Cups): If you absolutely must use measuring cups for flour, ensure you’re doing it correctly. Do not scoop flour directly with the cup. Instead, fluff the flour in its container with a spoon, then gently spoon it into your measuring cup until it overflows, and finally, level it off with the back of a knife. This prevents compacting the flour, which can lead to a dry, dense cake. You can refer to this guide for a visual demonstration.
• Embrace Overripe Bananas: This is non-negotiable for the best banana cake! Overripe bananas with plentiful dark spots or completely black skins are significantly sweeter and have a softer texture, making them easier to mash and ensuring your cake is incredibly moist and flavorful. Don’t skimp on this step!
• Room Temperature Ingredients: For both the cake and the frosting, having ingredients like eggs, buttermilk, sour cream, and butter at room temperature is vital. They emulsify much better, creating a smoother, more uniform batter and a creamier, lump-free frosting.
• Perfect Pan Lining: When lining your 8×8 baking pan with parchment paper, make sure to leave a generous overhang on two opposite sides. These flaps will act as convenient “handles,” allowing you to easily lift the fully cooled cake out of the pan without any sticking or breakage.
• Avoid Overmixing the Cake Batter: After adding the dry ingredients, fold them into the wet mixture gently with a rubber spatula. Mix only until no streaks of flour remain. Overmixing develops the gluten in the flour, which can result in a tough, chewy cake rather than a tender, moist one.
• Don’t Rush the Cooling Process: It’s tempting to frost a warm cake, but resist! Frosting a warm cake will cause the frosting to melt and slide off, creating a messy situation. Allow the cake to cool completely on a wire rack – typically at least 1-2 hours – before applying the frosting.

Frequently Asked Questions About Banana Cake

Expand Your Baking Repertoire! Try These Recipes Next!

Have you made this delightful banana cake with chocolate frosting? Please take a moment to rate the recipe below! We love to see your creations! Don’t forget to follow me on Instagram @alpineella and Pinterest, and tag us so we can share your baking triumphs!

For the Moist Banana Cake

• ▢ ½ cup unsalted butter melted and cooled
• ▢ 1 cup overripe bananas mashed (about 2-3 medium)
• ▢ ½ cup light brown sugar packed
• ▢ ¼ cup white sugar
• ▢ 2 teaspoons vanilla extract
• ▢ 2 large eggs room temperature
• ▢ ¼ cup buttermilk room temperature (or substitute)
• ▢ 1 teaspoon baking soda
• ▢ ½ teaspoon baking powder
• ▢ ½ teaspoon ground cinnamon
• ▢ ½ teaspoon kosher salt
• ▢ 1 ¾ cup all purpose flour

For the Decadent Chocolate Frosting

• ▢ 3 oz dark chocolate chopped, melted and cooled
• ▢ ½ cup unsalted butter softened, room temperature
• ▢ 1 cup confectioners’ sugar
• ▢ ½ cup cocoa powder unsweetened
• ▢ ¼ cup sour cream room temperature

For the Moist Banana Cake

• Preheat oven to 350°F (175°C). Grease and line an 8×8 inch (20×20 cm) baking pan with parchment paper, ensuring an overhang on two sides for easy lifting. Set aside.
• In a large microwave-safe bowl, melt the butter. Allow it to cool slightly, then whisk in the mashed overripe bananas until well combined.
  ½ cup unsalted butter, 1 cup bananas
• Add the white sugar and light brown sugar to the banana mixture. Whisk vigorously for about 1 minute until mostly dissolved.
  ¼ cup white sugar, ½ cup light brown sugar
• Whisk in the two large eggs, room temperature buttermilk, and vanilla extract until just combined. Don’t worry if the mixture still has a few banana lumps.
  2 large eggs, ¼ cup buttermilk, 2 teaspoons vanilla extract
• Add the dry ingredients: all-purpose flour, baking soda, baking powder, kosher salt, and ground cinnamon. Use a rubber spatula to gently fold everything together until no streaks of flour remain. Be careful not to overmix.
  1 teaspoon baking soda, ½ teaspoon baking powder, ½ teaspoon kosher salt, 1 ¾ cup all purpose flour, ½ teaspoon ground cinnamon
• Pour the batter into the prepared pan and bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean. Let cool in the pan for 20 minutes, then lift out using the parchment overhang and cool completely on a wire rack.

For the Decadent Chocolate Frosting

• Melt the chopped dark chocolate in a microwave-safe bowl in 15-second intervals, stirring after each, until smooth. Set aside to cool completely.
  3 oz dark chocolate
• In a stand mixer with a paddle attachment (or large bowl with a handheld mixer), beat the softened butter and confectioners’ sugar on low speed until combined. Increase to medium-high and beat for 2 minutes until light and fluffy.
  ½ cup unsalted butter, 1 cup confectioners’ sugar
• Add the cocoa powder and beat on low until just combined, then increase to medium speed and beat for another 2 minutes until smooth.
  ½ cup cocoa powder
• Pour in the cooled melted chocolate and room temperature sour cream. Mix once more on medium speed until everything is fully combined and the frosting is smooth and creamy. Scrape down the sides of the bowl as needed.
  ¼ cup sour cream
• Once the banana cake is completely cooled, spread the decadent chocolate sour cream frosting generously over the top. Slice into squares and serve!

Butter: For an extra rich and creamy bake, we use European-style unsalted butter, such as Kerry Gold. This type of butter has a higher fat content, contributing to a superior texture and flavor in your cake and frosting. Ensure it’s softened to room temperature for the frosting.

Salt: We specify Diamond Crystal Kosher Salt in our recipes, which is less dense than fine table salt. If you’re using a finer salt (like regular table salt), halve the amount called for to prevent your bake from becoming too salty. For example, 1 teaspoon of kosher salt equals approximately ½ teaspoon of fine salt. Avoid coarse kosher salt, as it can be too potent for this recipe.