Why You’ll Love These Banana Bread Brownies
These banana bread brownies are the perfect mash-up of two beloved classics, giving you the best of both worlds.
You’re getting that moist, banana-infused texture that banana bread is famous for, but in a convenient, hand-held brownie format with a to-die-for brown butter frosting.
I love how the ripe bananas add natural sweetness while keeping everything incredibly tender.
The walnuts give that perfect crunch contrast, and let’s talk about that frosting—it’s transformative. Brown butter adds a nutty, caramel-like depth that regular frosting just can’t touch.
They’re ideal for using up those spotty bananas on your counter.
What Ingredients are in Banana Bread Brownies?
To make these delightful banana bread brownies, you’ll need a handful of pantry staples plus those spotty bananas that have been waiting for their moment to shine.
The ingredients list might look a bit long at first glance, but it’s really divided into two parts—the banana bars themselves and that incredible brown butter frosting that takes them to the next level. Most of these items are probably already in your kitchen right now!
For the banana bread brownie base:
- 1 1/2 cups sugar
- 1 cup sour cream
- 1/2 cup butter, softened
- 2 eggs
- 3-4 bananas, mashed
- 2 teaspoons vanilla extract
- 2 cups all-purpose flour
- 1 teaspoon baking soda
- 3/4 teaspoon salt
- 1/2 cup walnuts, chopped
For the brown butter frosting:
- 1/2 cup butter
- 4 cups powdered sugar
- 1 1/2 teaspoons vanilla extract
- 3 tablespoons milk
The riper your bananas, the more pronounced the banana flavor will be in your brownies. Those dark, spotty bananas mightn’t look appetizing for eating fresh, but they’re absolutely perfect for baking—sweeter and easier to mash.
The walnuts add a wonderful textural contrast, but you could certainly omit them if you’re dealing with nut allergies, or swap them for chocolate chips if you want to make these even more indulgent.
And that brown butter frosting? Don’t even think about skipping it—browning the butter creates a nutty, caramel-like flavor that elevates these brownies from good to unforgettable.
How to Make These Banana Bread Brownies
Making these banana bread brownies is wonderfully straightforward, starting with preheating your oven to 375°F and preparing a 15×10-inch jelly roll pan with grease and flour.
In a large bowl, beat together 1½ cups sugar, 1 cup sour cream, ½ cup softened butter, and 2 eggs until you achieve a creamy consistency. This creates the rich base that makes these brownies so irresistible.
Next, blend in 3-4 mashed bananas (the spottier, the better!) and 2 teaspoons of vanilla extract, which infuses the batter with that classic banana bread aroma we all know and love.
Add the dry ingredients next—2 cups all-purpose flour, 1 teaspoon baking soda, and ¾ teaspoon salt—and blend for about a minute until everything is well incorporated.
Gently fold in ½ cup of chopped walnuts, which add the perfect textural contrast to the soft banana base.
Spread your batter evenly into the prepared pan, making sure it reaches all the corners, and pop it into the oven for 20-25 minutes, or until the top turns a beautiful golden brown.
While your brownies are baking, you can get started on that amazing brown butter frosting—trust me, it’s what makes these treats truly special.
For the frosting, heat ½ cup butter in a large saucepan over medium heat until it starts boiling.
Now, here comes the magic part: watch the butter carefully as it begins to turn a delicate brown color, then remove it from the heat immediately.
This browning process creates a nutty, almost caramel-like flavor that’s absolutely divine.
Quickly whisk in 4 cups powdered sugar, 1½ teaspoons vanilla extract, and 3 tablespoons milk until smooth.
The consistency should be thicker than a glaze but thinner than traditional frosting—perfect for spreading over your warm banana bread brownies.
Once your brownies have cooled slightly, use a spatula to spread this heavenly brown butter frosting evenly across the top, and then try your best to wait patiently before cutting them into squares and devouring them!
Banana Bread Brownies Substitutions and Variations
Now that you’ve mastered the basic recipe, let’s explore some creative substitutions and variations that’ll make these banana bread brownies uniquely yours.
For a healthier twist, swap white flour with whole wheat or almond flour—though you might need to adjust the moisture.
No sour cream? Greek yogurt works beautifully. Those avoiding nuts can substitute chocolate chips or dried cranberries.
I’ve tried adding a teaspoon of cinnamon and a pinch of nutmeg for a warm, spiced version that’s perfect for fall gatherings.
And for my gluten-free friends, a good quality one-to-one flour blend maintains that tender crumb we all crave.
What to Serve with Banana Bread Brownies
While these banana bread brownies are absolutely divine on their own, pairing them with complementary flavors can elevate your dessert experience to new heights.
I love serving mine with a scoop of vanilla ice cream that melts slightly into the warm brownie, creating that perfect hot-and-cold sensation. A drizzle of caramel sauce or a dollop of whipped cream works wonders too.
For brunch, I’ll often serve them alongside strong coffee or chai tea. The bitter notes in coffee particularly balance the sweetness.
Want something unexpected? Try them with a small glass of bourbon—trust me, the pairing is magical.
Final Thoughts
These banana bread brownies have become my absolute favorite way to transform overripe bananas into something truly special.
I’ve made them for potlucks, family gatherings, and those times when I need a little pick-me-up in the kitchen. The combination of moist, banana-infused base with that brown butter frosting? Pure magic, if you ask me.
What I love most is how forgiving this recipe is. Added an extra banana? No problem. Want to swap walnuts for chocolate chips? Go right ahead.
It’s that perfect balance of homey comfort and impressive presentation that keeps everyone coming back for seconds.

Heavenly Banana Bread Brownies
Ingredients
Equipment
Method
-
Preheat your oven to 375°F. Grease and flour a 15×10-inch jelly roll pan.
-
In a large bowl, beat together the sugar, sour cream, softened butter, and eggs until creamy and well combined.
-
Blend in the mashed bananas and vanilla extract until incorporated.
-
Add the flour, baking soda, and salt to the mixture. Blend for about one minute until well combined.
-
Gently fold in the chopped walnuts.
-
Spread the batter evenly into the prepared pan, ensuring it reaches all corners.
-
Bake for 20-25 minutes or until the top turns golden brown and a toothpick inserted in the center comes out clean.
-
While the brownies are baking, prepare the brown butter frosting. Heat the butter in a large saucepan over medium heat until it begins to boil.
-
Continue cooking, watching carefully as the butter turns a delicate brown color. Remove from heat immediately once it reaches a nutty, amber hue.
-
Quickly whisk in the powdered sugar, vanilla extract, and milk until smooth. The consistency should be thicker than a glaze but thinner than traditional frosting.
-
Allow the brownies to cool slightly, then spread the brown butter frosting evenly over the top.
-
Let cool completely before cutting into squares and serving.
Nutrition
Notes
These brownies can be stored in an airtight container at room temperature for up to 3 days or refrigerated for up to a week. You can also freeze unfrosted brownies for up to 3 months.
For a variation, try substituting the walnuts with chocolate chips or dried cranberries. You can also add a teaspoon of cinnamon and a pinch of nutmeg for a warm, spiced version.
Tried this recipe?
Let us know how it was!

Heavenly Banana Bread Brownies
Ingredients
Method
- Preheat your oven to 375°F. Grease and flour a 15×10-inch jelly roll pan.
- In a large bowl, beat together the sugar, sour cream, softened butter, and eggs until creamy and well combined.
- Blend in the mashed bananas and vanilla extract until incorporated.
- Add the flour, baking soda, and salt to the mixture. Blend for about one minute until well combined.
- Gently fold in the chopped walnuts.
- Spread the batter evenly into the prepared pan, ensuring it reaches all corners.
- Bake for 20-25 minutes or until the top turns golden brown and a toothpick inserted in the center comes out clean.
- While the brownies are baking, prepare the brown butter frosting. Heat the butter in a large saucepan over medium heat until it begins to boil.
- Continue cooking, watching carefully as the butter turns a delicate brown color. Remove from heat immediately once it reaches a nutty, amber hue.
- Quickly whisk in the powdered sugar, vanilla extract, and milk until smooth. The consistency should be thicker than a glaze but thinner than traditional frosting.
- Allow the brownies to cool slightly, then spread the brown butter frosting evenly over the top.
- Let cool completely before cutting into squares and serving.




