When ripe bananas start piling up on my counter, I usually make banana bread. This time I tried something different: an easy Brown Butter Banana Snack Cake with Sour Cream, topped with Salted Caramel Buttercream. It’s simple, moist, and the salted caramel frosting takes it to the next level.
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Making Easy Banana Cake
A few key elements make this snack cake stand out. First, the batter uses brown butter for a deep, nutty flavor. Browning butter is easy: melt unsalted butter over medium heat until it turns golden-brown and smells nutty. Scrape the browned bits from the pan — they add great flavor.
Next, use very ripe bananas — heavily spotted or almost black. Their natural sweetness powers most of the cake’s flavor, so this recipe uses only 1/4 cup granulated sugar plus 2 tablespoons dark brown sugar. The mashed bananas, combined with a small amount of sugar, create a wonderfully banana-forward cake.
Finally, full-fat sour cream keeps the cake tender and moist. It’s the same trick I often use in quick breads and other snack cakes.
Topping it off with Salted Caramel Buttercream
The salted caramel buttercream is optional but highly recommended. A small amount of homemade salted caramel folded into a classic buttercream produces a rich, balanced frosting that complements the banana cake perfectly.
If you prefer a tangier option, a cream cheese frosting works well too. For a different caramel-forward dessert, consider a cloud-soft Salted Caramel Cake with fudgy frosting.
Ingredients and Substitutions
See the recipe card below for exact measurements. Key ingredients and tips:
- Butter: Use unsalted butter so you can control salt. Brown it for extra flavor.
- Flour: All-purpose flour is recommended. Measure by spooning into the cup and leveling with a knife. I haven’t tested gluten-free or almond flour in this recipe.
- Sugars: Granulated sugar and a small amount of packed dark brown sugar provide balance. The bananas add most of the sweetness.
- Leavening & Salt: Baking soda and kosher salt.
- Bananas: Use very ripe bananas with lots of dark spots. If you don’t have ripe bananas, you can ripen them in the oven.
- Sour cream: Full-fat sour cream yields the best texture. Plain Greek yogurt can substitute in equal amounts.
- Eggs & Vanilla: Use large eggs at room temperature and real vanilla extract for better flavor.
Salted Caramel
- Granulated sugar
- Unsalted butter, room temperature and cubed
- Heavy cream
- Salt
Frosting
- Powdered (confectioners’) sugar
- Unsalted butter at room temperature
- Heavy cream
- Salted caramel sauce (from recipe above)
How to Make Banana Snack Cake
MAKE THE CAKE
STEP 1
Preheat the oven to 350°F. Line an 8×8-inch square pan with parchment, leaving at least a 2-inch overhang on two sides for easy removal. Butter the top of the parchment or spray with nonstick spray. A 9-inch pan can be used but the cake will be slightly thinner and may bake a few minutes less. Avoid glass pans as they can brown the edges before the center is done.
STEP 2
Brown the butter: melt 1/2 cup (1 stick) unsalted butter in a skillet over medium heat, stirring until it develops golden-brown flecks and a nutty aroma. Pour into a heatproof jar to cool slightly and scrape the brown bits into the jar.
STEP 3
Whisk the dry ingredients in a medium bowl: 1 1/2 cups all-purpose flour, 3/4 teaspoon baking soda, 1 teaspoon kosher salt, and 1/4 cup granulated sugar.
STEP 4
In a large bowl, whisk together 1 cup mashed ripe banana (about 2–3 bananas), 1/4 cup full-fat sour cream, 2 tablespoons packed dark brown sugar, 2 large room-temperature eggs, and 1 teaspoon vanilla extract.
STEP 5
Whisk in the cooled brown butter. Fold the dry ingredients into the wet just until combined — don’t overmix.
STEP 6
Scrape the batter into the prepared pan and smooth the top with a spatula or butter knife.
STEP 7
Bake until the top springs back when lightly pressed and a toothpick inserted in the center comes out clean, about 25 minutes. Let cool in the pan while you prepare the frosting.
STEP 8
Cool completely on a wire rack before frosting.
MAKE THE SALTED CARAMEL
STEP 1
In a medium saucepan over medium heat, stir 1/2 cup granulated sugar constantly. The sugar will clump, then melt into an amber liquid. Watch closely so it doesn’t burn.
STEP 2
When fully melted, add 3 tablespoons cubed unsalted butter (it may splatter) and whisk until incorporated.
STEP 3
Slowly drizzle in 1/4 cup heavy cream while stirring. Bring to a boil for one minute, then remove from heat and stir in 1/2 teaspoon kosher salt. Pour into a jar to cool; reserve a small amount for drizzling over the finished cake.
MAKE BUTTERCREAM
STEP 1
In a stand mixer fitted with the paddle attachment, beat 2 cups powdered sugar, 1/2 cup room-temperature unsalted butter, and 2 tablespoons heavy cream until light and fluffy, about 3–4 minutes.
STEP 2
Turn off the mixer and add 1/4 cup cooled salted caramel (reserve a little for a drizzle). Mix until evenly combined and smooth.
STEP 3
Spread the buttercream over the cooled cake, then drizzle the reserved salted caramel on top if desired. Use the parchment overhang to lift the cake from the pan and cut into 16 squares.
STEP 4
Serve and enjoy.
How to store this banana snack cake
Store leftover cake in an airtight container in the refrigerator for up to 4 days. Unfrosted banana cake can be frozen for up to 3 months. Leftover frosting keeps in a sealed jar in the refrigerator for up to 2 weeks.
Tips for Making This Recipe
- Use very ripe bananas with lots of dark spots for the best banana flavor. If bananas are not ripe, you can speed-ripen them in the oven.
- Brown the butter carefully over medium-low heat, stirring often, until it releases a nutty aroma and shows brown flecks. Don’t let it burn.
- Let the brown butter cool slightly before adding to the egg mixture to avoid scrambling the eggs.
- When melting sugar for the caramel, expect it to clump before it smooths into an amber liquid. Add the butter carefully (it may splatter) and have the cream ready to pour in slowly.
Enjoy this banana snack cake as a sweet treat or dessert. Cut into small squares and savor the combination of banana, brown butter, and salted caramel.
