Brown Butter Banana Bars topped with vanilla bean frosting offer the dense, fudgy texture of a brownie while showcasing the comforting flavor of moist banana bread.
This recipe yields a large sheet-pan batch, making it ideal for potlucks, parties, or any gathering where you want a crowd-pleasing dessert. Browned butter, sour cream, and ripe mashed bananas create a rich, tender crumb, while chopped walnuts add a pleasant crunch.
If you enjoy brownies and bars, these banana bars sit nicely alongside other favorites like banana bread brownies, pumpkin swirl brownies, beet brownies, and brown butter brownies.
What do they taste like?
The first bite makes you stop and savor the combination of warm banana flavor and the subtle nuttiness from brown butter. These bars deliver the classic banana bread taste, but with a denser, dessert-like texture—especially once they’re frosted.
Even those who claim not to like bananas often change their mind after trying these. They strike a balance between familiar comfort and indulgence, which is why this recipe feels like a timeless favorite that gets passed down.
The frosting is equally delicious.
These bars are wonderful on their own, but topping them with brown butter vanilla bean frosting elevates them into something truly special. The browned butter brings a subtle toasted, nutty note that pairs beautifully with banana and walnuts.
Vanilla beans can be pricey, but they add a distinct aroma and speckled appearance to the frosting. If you can, use them; the flavor payoff is worth the splurge.
Guess what… they freeze well too.
If you end up with more bars than you can eat in a few days, freezing is an excellent option. Bake the bars, cool completely, frost, and cut into individual portions.
To freeze, place the frosted bars on a tray in the freezer uncovered for about 30 minutes so the frosting firms up. Then wrap each bar in freezer paper or plastic wrap and store them together in a sealed freezer bag with excess air removed. This makes it easy to pull a single serving whenever you want one.
These bars slice neatly into uniform pieces, making them perfect for sharing—similar to classic lemon or orange bars.
Brown Butter Banana Bars
Ingredients
Banana Bars:
- 1/2 cup unsalted butter
- 1 1/2 cups sugar
- 1 cup sour cream
- 2 eggs beaten
- 1 1/2 cups bananas mashed, about 3 large or 4 small
- 1 tablespoon vanilla
- 2 cups all-purpose flour
- 1 teaspoon salt
- 1 teaspoon baking soda
- 1/2 cup chopped walnuts
Brown Butter Vanilla Bean Frosting
- 1/2 cup unsalted butter
- 2 vanilla beans split lengthwise
- 3 cups confectioner’s sugar
- 3 tablespoons milk or half and half more or less depending on desired thickness
Instructions
To make the banana bars:
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In a saucepan over medium heat, melt 1/2 cup unsalted butter. Whisk frequently and scrape the bottom as the butter foams. Continue cooking and stirring until the butter turns a light brown and smells nutty—be careful not to burn it—then remove from heat.
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Preheat the oven to 375°F. Line a 15½ x 10½-inch jelly roll pan with parchment paper or grease it.
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In the bowl of a stand mixer, combine the browned butter, 1 1/2 cups sugar, 1 cup sour cream, and 2 beaten eggs. Mix on low with the paddle attachment for about a minute. Scrape the bowl, add 1 1/2 cups mashed bananas and 1 tablespoon vanilla, and mix on low for another 30 seconds.
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In a separate bowl, whisk together 2 cups all-purpose flour, 1 teaspoon salt, and 1 teaspoon baking soda. Add the dry ingredients to the wet and mix on low just until combined, then briefly beat on high for about 10 seconds. Scrape the bowl, fold in 1/2 cup chopped walnuts, and spread the batter evenly in the prepared pan.
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Bake in the preheated oven until the top is light brown and a toothpick comes out clean, about 20 to 25 minutes. Allow the pan to cool completely before frosting.
To make the frosting:
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In a saucepan over medium heat, melt 1/2 cup unsalted butter with 2 split vanilla beans. Whisk and scrape the insides of the vanilla beans into the butter as it foams. Cook until the butter turns light brown and fragrant, then remove from heat. Remove the pods, scrape any remaining seeds back into the butter, and set aside to cool slightly.
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In a stand mixer fitted with the whisk attachment, beat the browned vanilla bean butter with 3 cups confectioner’s sugar. Begin on low to combine, then increase the speed to medium and high until the frosting is light and fluffy.
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Add 3 tablespoons milk or half-and-half one tablespoon at a time, beating until you reach the desired consistency. Use a little more or less liquid depending on how thick you prefer the frosting.
Frost and serve:
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Once the bars are completely cool, spread the brown butter vanilla bean frosting over the top. Slice into individual bars and serve. Store any leftovers in an airtight container; these freeze well for longer storage.
Notes
Nutrition
Nutrition information is automatically calculated and should be used as an approximation.
This post was originally published in January 2016 and has recently been updated for your reading pleasure.