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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.
Always a hit! I’ve made this a few times now and everyone loves it. It’s easy and really does freeze very well.
First time success with modifications! I used one cup of unbleached flour, but the other cup consisted of two heaping tablespoons of soy flour and the remainder whole wheat. I also added two heaping tablespoons of ground flax seed. In half of my baking pan, the batter included chopped black walnuts; much to my delight, these make a wonderful combination with the banana flavor!! I also reduced the sugar in the recipe so it was a little more than half of what is in the original recipe. I can’t wait to share with my neighbors after making these for breakfast on the day after my birthday!
I made this a weeks ago and the recipe has 3 cups of powdered sugar for the frosting. Now your recipe says 2 cups fo powdered sugar. The first time I made the frosting it seemed like way too much. However, with the 2 cups, it didn’t seem like quite enough.
These bars are delicious! I didn’t add the brown butter glaze but that didn’t take away from the flavor. They were so light and fluffy and absolutely scrumptious.
Wow! Yum yum yum! Delicious. And easy!
Thank you for sharing!
These are are worth buying bananas for and waiting for them to over ripen. I made them for the second time today using 3/4 cup sugar and the “lightened up” frosting. The only thing I added on my own was 1 tsp cinnamon. Delicious!
This recipe is INCREDIBLE. You have made this little family so happy!
Also, forgot to mention that the second time I made this recipe, I ran out of vanilla extract. So I substituted almond extract and it was suuuuper yummy 🙂
These came out amazing. Everyone raved about the frosting. Salty and sweet when warmed up. Definitely better served warm (15 to 20 secs in microwave). Can I make muffins with this recipe?
Yes, sure!
This recipe is sooo moist and delicious! I omitted the frosting and used cool whip instead
WOW. Just WOW. These are AMAZING. I’ve gotten tired of banana bread and banana smoothies and wanted to find a new recipe for using up over-ripe bananas. I’m so impressed with this recipe. It is dense, and moist, and the brown-butter frosting just takes it over the top. It’s also very easy to make. Thanks for the great recipe! (For mine: I used 4 bananas and didn’t have yogurt so used sour cream. I needed about 3-4 TBS of milk for my frosting, and I used soymilk bc that’s what I had on hand. I might cut down on sugar both in batter and frosting next time because bananas are already so sweet, but I wanted to make it exactly as the recipe the first time.) Thanks again! This one is a keeper!