A high altitude recipe for a one layer banana snack cake that’s moist like banana bread, frosted with fluffy chocolate buttercream. The combination of banana cake with chocolate frosting and a hint of cardamom is just delicious!
You might also love these one layer cake recipes for walnut chocolate chip cake, chocolate chestnut cake, and almond cake.
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Why You’ll Love This Recipe
As Easy as Banana Bread. I based today’s banana bread cake on my popular recipe for banana bread, which is so moist, tender and flavorful. The only change I made to the cake batter was to replace some of the mashed banana with milk, to make it a bit less bready and a little more cakey. The batter comes together quickly with just a bowl and whisk.
Moist for Days. Even days after baking, this banana snack cake is still so soft and moist.
Smaller Size. Today’s cake is a modest, one layer 8-inch cake. For a larger size, you can double the recipe and bake it in a 9×13 pan.
High Altitude Tested. I develop all the recipes on my site for Denver’s altitude of 5,280 feet. If you’re at a lower or higher elevation, please see my FAQs for guidance on adjusting recipes for your altitude.
See the recipe card at the end of the post for the full ingredients list and instructions.
Ingredients
Cake
- Bananas. You want to use very soft, over-ripe bananas with lots of speckles and brown spots. Their sweeter flavor makes the best baked goods.
- Sugar. A combination of granulated sugar and light brown sugar adds sweetness and moisture.
- Eggs. Gives the cake structure and moisture.
- Vanilla Extract. Flavor.
- Milk + Sour Cream. Use full fat dairy for a tender, flavorful cake.
- Butter. Adds moisture, flavor and richness.
- Flour. All-purpose flour gives the cake structure and strength.
- Baking Soda + Baking Powder. Leavening agents, which make the cake rise.
- Salt. Balances the sweetness and enhances the flavors.
- Cardamom. A pinch of cardamom adds some complementary spice to the bananas and chocolate.
Buttercream
- Butter. You can use either salted or unsalted butter. If using salted, just omit the extra salt in the recipe.
- Powdered Sugar. Sweetens and thickens the buttercream.
- Cocoa Powder. Unsweetened cocoa powder, preferably Dutch processed, for a rich chocolate flavor.
- Meringue Powder. Adds stability and improves the texture.
- Salt. Balances the sweetness.
- Vanilla Extract. Flavor.
Instructions
Cake
- Preheat the oven to 350 F, and position a rack in the center of the oven. Lightly grease an 8-inch square baking pan with non-stick baking spray, or line the pan with parchment paper.
- In a bowl, whisk together the mashed bananas, sugar, brown sugar, eggs and vanilla. Whisk in the sour cream, milk and melted butter.
- Separately, sift together the flour, baking soda, baking powder, salt and cardamom, then whisk until evenly distributed. Add the dry ingredients to the wet, and whisk briefly, just until combined. (The batter is thick, and a spatula is easier to use than a whisk for this step.)
- Spread the batter into the prepared pan. Bake for about 30-35 minutes, until a toothpick or cake tester inserted in the center of the cake comes out clean.
- Set the cake on a cooling rack, and cool completely before frosting.
Buttercream
- In the bowl of your stand mixer fitted with the paddle attachment, beat the butter for one minute until smooth.
- With the mixer on low, add the powdered sugar, cocoa powder, meringue powder and salt, mixing until combined. Add the vanilla. Increase the speed to medium, and whip for 4-5 minutes, scraping the bowl down several times, until very light and fluffy.
- Spread the buttercream on top of the cooled cake.
Be sure to read all of my BAKING FAQs where I discuss ingredients, substitutions and common baking questions, so that you can be successful in your own baking!
Frequently Asked Questions
Can I use a 9 inch pan instead of an 8 inch pan?
Yes, you can. Your banana snack cake will be a little thinner, and you should bake it for a few minutes less.
Can this recipe be doubled?
For a larger quarter sheet cake, double the recipe and bake the cake in a 9×13 inch baking pan.
What if I want to add nuts to the cake batter?
Go for it! A half cup of chopped walnuts or pecans would be wonderful in a chocolate banana cake.
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Banana Snack Cake with Chocolate Buttercream
All recipes on Curly Girl Kitchen are developed for high altitude at 5,280 feet. See FAQs for adjusting to higher or lower elevations.
Equipment
- Stand Mixer with Paddle Attachment
Ingredients
Cake
- 1 cup mashed, over-ripe bananas (from 2-3 small/medium bananas)
- ½ cup granulated sugar
- ¼ cup light brown sugar, lightly packed
- 2 large eggs
- 2 tsp vanilla extract
- ½ cup full fat sour cream
- ½ cup whole milk
- 6 tbsp unsalted butter, melted
- 2 cups all-purpose flour, fluffed, spooned and leveled
- ¾ tsp baking soda
- 1 tsp baking powder
- ½ tsp coarse Kosher salt (if using table salt, use half the amount)
- ¼ tsp ground cardamom
Buttercream
- ¾ cup unsalted butter, softened to room temperature
- 1 cup powdered sugar
- ½ cup unsweetened, Dutch processed cocoa powder
- 1 tsp meringue powder (optional)
- ⅛ tsp coarse Kosher salt (if using table salt, use half the amount)
- 1 tsp vanilla extract
Instructions
Cake
- Preheat the oven to 350 F, and position a rack in the center of the oven. Lightly grease an 8-inch square baking pan with non-stick baking spray, or line the pan with parchment paper.
- In a bowl, whisk together the mashed bananas, sugar, brown sugar, eggs and vanilla. Whisk in the sour cream, milk and melted butter.
- Separately, sift together the flour, baking soda, baking powder, salt and cardamom, then whisk until evenly distributed. Add the dry ingredients to the wet, and whisk briefly, just until combined. (The batter is thick, and a spatula is easier to use than a whisk for this step.)
- Spread the batter into the prepared pan. Bake for about 30-35 minutes, until a toothpick or cake tester inserted in the center of the cake comes out clean.
- Set the cake on a cooling rack, and cool completely before frosting.
Buttercream
- In the bowl of your stand mixer fitted with the paddle attachment, beat the butter for one minute until smooth.
- With the mixer on low, add the powdered sugar, cocoa powder, meringue powder and salt, mixing until combined. Add the vanilla. Increase the speed to medium, and whip for 4-5 minutes, scraping the bowl down several times, until very light and fluffy.
- Spread the buttercream on top of the cooled cake.
My husband said this is the best cake he’s ever eaten! We love how dense it is. Amazing and easy!