Brown butter banana bread sheet cake takes a standard flavor combination and adds brown butter and cinnamon to bring a new level of interest to this old favorite. A creamy, buttery, chocolate ganache topped with fresh bananas and chopped nuts makes the whole thing divine.
If you were to ask any of my family and friends what I am known for, they would unanimously say my cakes. I grew up with a huge affinity for creating different cake and cupcake flavors, so this sheet cake might be described as simplistic in nature but it’s 100% guaranteed to be a delight from the first bite and can only be described as beautiful and delicious!—Amie MacGregor
☞ Table of Contents
Brown Butter Banana Bread Sheet Cake FAQs
Why do I do if my chocolate ganache curdles?
If the chocolate icing starts to take on a grainy or curdled appearance, it’s possible that it got too warm and the fat has separated out of the chocolate. To fix this, add 2 tablespoons of warmed cream to the ganache while whisking it vigorously until it smooths out. Add more cream if it still hasn’t come together.
What are some tips for making brown butter?
Use a light-colored saucepan so you can see the solids browning. This way you’ll know when it’s ready. It’s also helpful to cut your butter into smaller pieces so that it melts faster and cooks more evenly. Finally, don’t get impatient and jack up the heat. Brown butter doesn’t take long and will burn very quickly.
My bananas aren’t ripe. How can I ripen them quickly?
The quickest way is by putting them in the oven. Place your bananas, still in their peels, on a lined, rimmed baking sheet (because they ooze, sometimes). Turn the oven to 300°F and bake until their peels turn black. Let them cool a few minutes before handling. And you’ve got yourself some sweet, mushy bananas for baking.
Brown Butter Banana Bread Sheet Cake
For the chocolate ganache frosting
- 1 cup heavy cream
- 3/4 cup granulated sugar
- 6 tablespoons (3 oz) unsalted butter at room temperature
- 6 ounces semisweet chocolate finely chopped
- 3/4 teaspoon vanilla extract
For the brown butter
- 1 stick (4 oz) unsalted butter at room temperature
For the banana bread sheet cake
- Cooking spray
- 2 cups all-purpose flour
- 2 teaspoons baking powder
- 1 teaspoon baking soda
- 1/2 teaspoon table salt
- 1/2 teaspoon ground cinnamon
- 1 1/4 cups packed dark brown sugar
- 1 cup plus 2 tablespoons mashed overripe bananas
- 3/4 cup sour cream
- 1/2 cup mild vegetable oil
- 3 large eggs
- 1 1/2 teaspoons vanilla extract
- 1 banana sliced, for decorating
- 1/3 cup walnuts or pecans for decorating
Make the chocolate ganache frosting
- In a medium saucepan over medium heat, combine the cream, sugar, and butter. Heat until the mixture begins to bubble, 3 to 4 minutes.
- Cover the ganache with plastic wrap, then place it into the fridge to chill for at least 3 to 4 hours, or preferably overnight.
Make the brown butter
- In a small saucepan over medium heat, melt the butter and bring to a boil. Continue heating, stirring constantly, until the butter has turned a nutty brown color, 5 to 6 minutes. It may be hard to see the color if your butter is foaming a lot, so periodically take it off the heat to check the color. Remove the butter from the heat and place it in a heatproof bowl to cool for 15 minutes.
Make the banana bread sheet cake
- Preheat the oven to 350°F (175°C). Coat a 9-by-13-inch (23-by-33 cm) baking sheet with cooking spray and line with parchment paper.
- In a medium bowl, combine the flour, baking powder, baking soda, salt, and cinnamon. Whisk until well combined.
- In a separate large mixing bowl, combine the browned butter, brown sugar, mashed bananas, sour cream, vegetable oil, eggs, and vanilla, then whisk until well combined. Add the dry ingredients to the wet ingredients, then whisk until a smooth batter comes together.
- Pour the batter into the prepared baking sheet and bake until a toothpick inserted in the center comes out clean, 25 to 35 minutes. Allow the cake to cool completely before frosting.
- Remove the ganache from the fridge and transfer it to a stand mixer fitted with the whisk attachment. Beat on high speed until fluffy. Smooth the ganache over the cooled cake with a spatula and garnish with the sliced banana and nuts.
Recipe Testers’ Reviews
This brown butter banana bread sheet cake recipe drew me in with the magic combination of chocolate and bananas. Plus, it is easy to make, moist and tender with a slightly nutty flavor.
I used a light-colored pan to prep the browned butter which allowed me to see the butter change color more easily—this step takes mere minutes. Much of the flavor is in those browned bits of milk solids in the bottom of the pan so I stirred those into the cake batter, too. This cake is perfect for bringing to a picnic, potluck, or for after-school snacks.
The mark of a good sheet cake? Is it worthy of a potluck invitation and would it sway someone from the old Texas chocolate sheet cake standby? And yes, this brown butter banana bread sheet cake definitely delivers.
The cake layer is a perfect cake version of banana bread and the ganache layer really makes you believe bananas should always be combined with chocolate. The brown butter, which I confess to almost forgetting to add as it sat aside to cool itself, is the secret to this delicious cake—it takes it from average to ‘can’t stop eating it, please take it away!’
This isn’t the banana bread you make to tuck into your kid’s school snacks or the one you have with your afternoon tea. This is banana bread all dressed up and ready for the party. And what a party it is.
This brown butter banana bread sheet cake turns out a rich, moist banana cake with a hint of cinnamon and nuttiness from the browned butter. The ganache frosting steps up the indulgence and the scattering of nuts and banana slices make an oh-so-pretty cake. Delightful!
Originally published December 14, 2021