Banana Bread Brownies

Why You’ll Love This Recipe

I love this recipe because it transforms simple ingredients into something truly indulgent. The ripe bananas make the bars naturally sweet and moist, while the walnuts add just the right crunch. The brown butter frosting is what takes them over the top — nutty, rich, and perfectly balanced against the sweetness of the bars. Plus, they come together quickly and bake in just 25 minutes, making them an easy dessert for any occasion.

Ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

For the Brownies:

• 2 eggs

• 3 ripe bananas, mashed

• 1 ½ cups sugar

• 1 cup sour cream

• ½ cup butter, softened

• 2 teaspoons vanilla extract

• 2 cups all-purpose flour

• 1 teaspoon baking soda

• ¾ teaspoon salt

• ½ cup walnuts, chopped

For the Frosting:

• ½ cup butter

• 3 cups powdered sugar

• 1 ½ teaspoons vanilla extract

• 3 tablespoons milk

Directions

1. I preheat the oven to 375°F (190°C) and grease a 13×9-inch baking pan.

2. In a large bowl, I beat together the sugar, sour cream, softened butter, and eggs until creamy and smooth.

3. I fold in the mashed bananas and vanilla extract for that classic banana bread flavor.

4. I gradually add the flour, baking soda, and salt, mixing just until combined to avoid overmixing.

5. I stir in the walnuts, then spread the batter evenly into the prepared pan.

6. I bake for about 25 minutes, or until golden brown and a toothpick inserted in the center comes out clean.

7. While the brownies cool, I make the frosting by browning the butter in a saucepan over medium heat until it turns a warm golden color.

8. Off the heat, I whisk in the powdered sugar, milk (a little at a time), and vanilla extract until smooth and spreadable.

9. I pour the frosting over the warm (but not hot) brownies, spreading it evenly.

10. Once fully cooled, I slice them into squares and serve.

Servings and timing

This recipe makes 12 brownies. The total time is about 40 minutes — 15 minutes of prep and 25 minutes of baking.

Variations

• Nut-free version: I leave out the walnuts for a smoother texture.

• Extra flavor: A pinch of cinnamon or nutmeg adds warmth to the batter.

• Chocolate twist: I stir in chocolate chips for a more brownie-like bite.

• Gluten-free option: I substitute a 1:1 gluten-free flour blend.

• Frosting alternative: I sometimes top with cream cheese frosting if I want something tangier.

Storage/Reheating

I store the brownies in an airtight container at room temperature for up to 3 days, or in the fridge for up to a week. For longer storage, I freeze them (unfrosted or frosted) for up to 2 months, separating layers with parchment paper. To serve, I let them thaw at room temperature or warm them briefly in the microwave for a soft, fresh-baked feel.

FAQs

Can I use frozen bananas?

Yes, I thaw frozen bananas and drain any excess liquid before mashing. They work just as well as fresh overripe bananas.

Do I have to brown the butter for the frosting?

No, but I highly recommend it — the nutty, caramel-like flavor of browned butter really makes the frosting special.

Can I make these ahead of time?

Yes, I often bake them a day ahead. The flavor actually deepens after sitting overnight, and the frosting holds up beautifully.

Why are my brownies dense?

Overmixing the batter can make them dense. I stir just until the ingredients are combined for the best texture.

Can I bake this recipe in a smaller pan?

Yes, I’ve made them in an 8×8-inch pan for thicker brownies, though the bake time increases slightly.

Conclusion

These Banana Bread Brownies are the perfect blend of comforting and decadent — soft, moist banana bars topped with a rich brown butter frosting that makes them irresistible. I love how they’re easy enough for everyday baking but special enough to serve at a party. They’ve become one of my favorite ways to use up ripe bananas, and I never get tired of that sweet, nutty, frosted bite.

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