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We enjoy every last bite of these cake-like banana bread bars because they never last long when I make them. The brown butter frosting is only 4 simple ingredients and makes them outstanding. You can customize the bars by adding nuts or chocolate chips instead of frosting, and I like to cut them into small squares for a bite size after school treat.
How to Make Banana Bread Brownies:
Mix we Ingredients: Cream butter and sugar: Beat in the sour cream and eggs, bananas and vanilla extract.
Add dry ingredients: flour, baking soda, salt, and mix just until moistened. Stir in walnuts, if using.
Bake: Pour batter into a 9×13 inch baking pan or half sheet pan. For a 9×13’’ pan, bake for 23-28 minutes or until a toothpick inserted in the center comes out clean or with few crumbs.

Make the glaze: Heat butter over medium heat and allow it to come to a simmer until it turns a delicate brown (watch carefully so you don't burn the butter). Remove from heat immediately. Whisk in the powdered sugar, vanilla extract and milk until smooth.
Pour Glaze over Bars: This is easiest when the bars are warm. Spread gently with the back of a spoon.

Recipe Variations:
- Add nuts: add chopped walnuts or pecans to the batter before baking.
- Add chocolate chips: add mini milk or semi sweet chocolate chips.
- Change the frosting: I love the brown butter frosting but this cream cheese frosting would also be delicious.
- Healthier banana bread bars: cut the sugar in half for a lighter version and use 3-4 Tbs of butter for the frosting instead of 6.
Make Ahead And Freezing Instructions:
To make ahead: bake and frost them one to two days ahead of time. Store them covered, in the refrigerator.
To freeze: allow them to cool completely and freeze them frosted or unfrosted right in the pan. Cover them well with plastic wrap and aluminum foil before freezing and freeze for up to 3 months. Allow to thaw completely before serving.
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Banana Bread Brownies
Ingredients
For the Banana Bread Bars:
- 1-1/2 cups granulated sugar
- 1 cup plain Greek yogurt, (or sour cream)
- 1/2 cup butter, softened
- 2 large eggs
- 3-4 ripe bananas, mashed
- 2 teaspoons vanilla extract
- 2 cups all-purpose flour
- 1 teaspoon baking soda
- 3/4 teaspoon salt
For the Glaze:
- 4 Tablespoons butter
- 2 cups powdered sugar
- 1 teaspoon vanilla extract
- 1-2 Tablespoon milk
Instructions
- Preheat oven to 375 degrees F and grease a 9×13 inch pan with non-stick cooking spray.
- In a large bowl, cream together the sugar and butter. Beat in the sour cream and eggs, bananas and vanilla extract.
- Add the flour, baking soda, salt, and mix just until moistened. Stir in walnuts, if using.
- Spread batter evenly into prepared pan and bake for 23-28 minutes or until a toothpick inserted in the center comes out clean, or with few crumbs. Make frosting while the bars bake.
For the Brown Butter Frosting:
- Heat the butter in a large skillet over medium heat. Allow it to come to a simmer until it starts to turn a delicate brown and has a nutty aroma (watch carefully so you don't burn the butter!) Remove from heat immediately.
- Whisk in the powdered sugar, vanilla extract and 1 tablespoon of milk until smooth. (Add a little more powdered sugar, or milk, if needed to thicken or thin the frosting). Pour the warm frosting over the warm bars. Spread gently with the back of a spoon.
Notes
- Add nuts: add chopped walnuts or pecans to the batter before baking.
- Add chocolate chips: add mini milk or semi sweet chocolate chips to batter before baking.
- Change the frosting: I love the brown butter frosting but this cream cheese frosting would also be delicious.
- Healthier banana bread bars: cut the sugar in half for a lighter version and use 3-4 Tablespoons of butter for the frosting instead of 6.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
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I originally shared this recipe June 2017. Updated January 2021.
Process photos by Nikole from The Travel Palate.




Yes! A really good brownie banana cake that was a huge hit with all my family. Moist, delicious and I didn’t even ice them, just put extra chocolate chips and walnuts on top. Yummy! Ten stars!
I made these banana bread brownies last night…. they are quite possibly one of my top 5 desserts of all time!!!! SO DELICIOUS!!!!!! I will continue to make and enjoy this dessert! Thank you.
I made these and they were marvelous! I wondered if you could half the recipe to put in a square pan… Would that work and would the time/temperature remain the same? I want to give them away in an aluminum square pan. Thanks for any info!
Hi Ann!
I was just wondering the same thing!!
I want to make them in a square 8 x 8 pan. I may try halving the recipe and see how they come out.
I’ll be happy to share the outcome when I try it!
Easy to put together, AND tasty! Had to bake them an extra 8 minutes beyond the 28 minutes. Still a little doughy in about a 6 bar area. I cut them into 24 bars for a church potluck. Will lessen the amount of moisture before I try them again. I don’t see any other comments about this problem.
I have been making these for years…couldn’t figure out what I had forgotten. It was baking POWDER. 1/2 tsp. They are good, but different texture without the baking powder. 🖤
I made this today and everyone loved it. I forgot to sift the powdered sugar, so my glaze had little lumps in it, but it did not hurt the flavor at all. As I was spreading it over the cake, I was thinking that I wished I had doubled it, because it didn’t seem like enough. But it was, because it is VERY sweet. This would indeed also be amazing with cream cheese frosting. Thanks for the recipe!
The best banana sweet ever. Yum. Thx for sharing!
Absolutely delicious, super recipe!!
I made this for dessert tonight, and my dad and husband raved about it. It had the best banana flavor, and the glaze was just the perfect touch of sweetness without being overwhelming. I used Greek yogurt, and it made the bars light and fluffy.
Could you make this a muffins? If so how long should I bake for and at what temp? Thank you!
I haven’t baked them in a muffin tin but yes that would be fine, at the same temp.
I was wondering if i could do bundt cakes with this recipe?
I have been making this recipe for over 10yrs.. However, my spin is to add blueberries to the batter. Mmm mmm good! 😃