Banana Bars with Brown Butter Frosting are one of the best ways to use up overripe bananas. They are a mix between banana cake and banana blondies, topped with the most delicious frosting.
These moist banana bars are easy to make and will be loved by the whole family! If you love brown butter as much as we do then try Brown Butter Toffee Chocolate Chip Cookies!
Brown butter buttercream is one of my favorite frostings. Brown butter has a nutty toffee or caramel like flavor and goes so well with many sweets and savory dishes too.
This banana bar recipe is perfect for any occasion, just like Taffy Apple Salad. We bake this dessert for birthday parties, picnics, holiday parties and to put in my kids' lunches.
They also go great alongside pork burgers!
If you love banana recipes then try my Chocolate Espresso Banana Bread and Strawberry Banana Smoothie Bowl
Jump to:
What Is Brown Butter?
Brown butter is butter that has been heated on the stove top until it becomes brown with nutty, toffee or caramel like aroma and taste. It is basically liquid gold. It adds such a unique and wonderful flavor to sweet and savory dishes.
One of my favorite savory dishes to use it in is Sweet Potato Pudding!
How To Make Brown Butter
Making brown butter is really easy. I know a lot of people are intimidated or scared to try it. There are really just a few simple steps:
- Melt your butter in a sauce pot over medium - low heat. Stir it occasionally to ensure even melting
- The butter will start sputtering and crackling. This is normal, it's what you want. This is when you need to keep a close eye though
- Swirl the butter around every 20 seconds or so. You can also stir it with a whisk or wooden spoon
- The butter will start to brown slightly on the bottom of the pan. You know the butter is ready when it "quiets down". The butter will stop sputtering and making noise and that's when it's perfect to take off. The butter should be a nice golden amber color
- Immediately pour the butter out of the pan into a heat proof container and set it aside until needed. Go ahead and use a rubber spatula to get all of the butter and the brown specks too. Now you have browned butter! Try it in Brown Butter Graham Cracker Blondie S'mores too!
Recipe Ingredients
- Butter - I use unsalted butter so that I can control the salt level myself.
- Brown Sugar - Generally I use dark brown sugar but either light or dark would be fine.
- Eggs - Room temperature eggs are best for this recipe.
- Bananas - Overripe bananas provide the best flavor when baking. Try them in no bake Banana Pudding Cheesecake Squares or Banana Coffee Cake!
- Rum Extract - Found at your local grocery store near the vanilla extract.
- Kosher Salt - It makes a difference whether you're using kosher salt or not. I use Diamond Crystal brand.
- Baking Powder - For just a little rise in the banana bars.
- Powdered Sugar - Sift your powdered sugar before adding it to the frosting.
- Milk - I use whole milk but whatever you prefer is fine, including plant based milks.
- Flaky Sea Salt (optional) - I always like a little flaky salt on top of my desserts. Try it on Chocolate Raspberry Tart!
Substitutions & Variations
- Try adding chocolate chips, walnuts or pecans. Chocolate chip banana bars are always a hit.
- This banana bar recipe is great with traditional cream cheese frosting or brown butter cream cheese frosting too! Grab the cream cheese frosting recipe from Cinnamon Toast Crunch Cookies!
- Make this recipe with or without rum extract.
- I use whole milk but any cow's milk or plant based milk can be substituted.
How To Make Banana Bars With Brown Butter Frosting
Step 1: Preheat the oven to 350°F then spray the 8x8 inch pan with non-stick cooking spray, line it with parchment paper. Whisk the melted butter and brown sugar together until smooth in a large bowl.
Step 2: Mash bananas and set aside.
Step 3: Stir in the eggs one at a time. Add the vanilla and rum extracts then stir in the mashed banana.
Step 4: In a separate bowl whisk the flour, salt and baking powder together in a medium bowl.
Step 5: Fold the dry ingredients into the wet ingredients just until combined. Do not over mix.
Step 6: Pour the batter into prepared pan and spread evenly. Bake for 30 minutes or until a toothpick comes out clean or with only a few crumbs. Allow the banana bars to cool completely on a wire rack.
Step 7: Add the cooled brown butter and sifted powdered sugar into the bowl of a stand mixer fitted with the paddle attachment. Mix on low until combined then turn up to medium for 1 minute. Add the vanilla, milk and salt. Mix on low until combined then mix on medium - high for 4 minutes until light and fluffy.
Step 8: Once banana bars are cooled then spread the frosting over the top and serve
Expert Baking Tips
- After making the brown butter frosting, beat it for a minute with a rubber spatula to get some of the air out before spreading it on the bars.
- Make sure the banana bars are fully cooled before frosting them. Otherwise the frosting will melt.
- Use overripe bananas for this recipe. You can also use them in Chocolate Espresso Banana Bread!
- Room temperature ingredients will provide you with the best results.
- The brown butter frosting recipe can be made up to 3 days ahead of time then stored in an airtight container in the fridge. Let it come to room temp before frosting the banana bars.
Recipe FAQs
Want to make these Banana Bars with Brown Butter Frosting but don't have any overripe bananas?! You always want to use overripe bananas in baking, they provide the best banana flavor.
Don't worry, there are a few hacks you can use to go from yellow bananas to brown bananas. These tips are for ripening bananas to bake with, not to eat as a raw snack. I use this when I'm craving Banana Bread with Streusel Topping.
This is one of the best baking hacks. Now you don't have to wait for days while you have a craving for the best banana bars. You can use your bananas no matter what stage they're in!
You can bake bananas. Preheat the oven to 300°F then line a baking sheet with parchment paper. Place the bananas on the sheet then bake for 20-30 minutes. You'll want the bananas to be very dark brown - black. Remove them from the oven, let them cool then peel and use them!
You can also microwave the bananas. Alternatively, you can microwave the bananas to speed up the ripening process. Microwave your bananas for 30 seconds and check for brownness. If they aren't quite brown yet then continue to microwave in 15 second intervals until you've reached desired color.
I will say, I prefer the oven method over the microwave if you're in a pinch and don't have overripe bananas but either will work.
Yes, absolutely! If you have leftover bananas that are overripe then you can freeze them. Just thaw out the frozen bananas prior to using them for baking. Here's my favorite way to freeze them:
Peel the banana then discard the skin. Place the banana into a plastic re-sealable bag. I like to use 2 bags to help prevent freezer burn. Put a date on the bag then freeze the bag of banana. Keep them frozen for up to 3 months. Try them in Honey Banana Bread too!
Store them on the counter in an airtight container or tightly double wrapped with plastic wrap. The banana bars will last up to 3 days on the counter.
You can also store them in the fridge in an airtight container or tightly double wrapped with plastic wrap. Storing them in the fridge will give them a little extra shelf life of six days. Although they are still delicious when chilled, I would recommend bringing the banana bars to room temp on the counter before eating.
Lastly, you can store them in the freezer. To store the banana bars in the freezer, make sure they are fully cooled first. You can store them in the freezer with or without the frosting. Wrap them tightly in plastic wrap 2-3 times then in aluminum foil 1 time. They will last in the freezer for up to 2 months
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📖Recipe
Banana Bars with Brown Butter Frosting
Equipment
- 1 large and medium mixing bowls
- 1 8x8 inch metal baking pans
- 1 whisk
- 1 rubber spatula
Ingredients
Wet Ingredients
- 1 cup unsalted butter melted then cooled slightly
- 1¾ cup brown sugar
- 2 eggs room temp
- 2 teaspoon vanilla extract
- 2 teaspoon rum extract
- 1 cup mashed banana overripe
Dry Ingredients
- 2 cups all purpose flour
- ½ teaspoon kosher salt
- ½ tsp baking powder
Brown Butter Frosting
- 1 cup brown butter cooled
- 2 cups powdered sugar sifted
- ½ tsp vanilla extract
- 1 tablespoon whole milk
- ¼ tsp kosher salt
Toppings (OPTIONAL)
- ¼ tsp flaky sea salt on top of the frosted banana bars
- 1 banana sliced, placed on top of frosted banana bars
Instructions
Mixing the Wet Ingredients
- Preheat the oven to 350°F then spray an 8x8 inch pan with non stick cooking spray, line it with parchment paper and spray the parchment paper with non stick spray
- Whisk the melted butter and brown sugar together until smooth in a large bowl
- Stir in the eggs one at a time
- Add the vanilla and rum extracts then stir in the mashed banana and set aside
Mixing the Dry Ingredients
- Whisk the flour, salt and baking powder together in a medium bowl
- Fold the dry ingredients into the wet ingredients just until combined. Do not over mix. A few streaks of flour are fine
- Pour the batter into prepared pan and spread evenly. Bake for 30 minutes or until a toothpick comes out clean or with only a few crumbs
- Allow the banana bars to cool completely on a wire rack
Making the Brown Butter Frosting
- While the banana bars are cooking, add the cooled brown butter and sifted powdered sugar into the bowl of a stand mixer fitted with the paddle attachment
- Mix on low until combined then turn up to medium for 1 minute
- Add the vanilla, milk and salt. Mix on low until combined then mix on medium - high for 4 minutes until light and fluffy
- Once banana bars are cooled then spread the frosting over the top and serve
- Top with flaky sea salt or sliced banana if you like
Krista
This is my go-to bake for friends and family. Everyone always enjoys them and asks for the recipe!
Nicole
Amazing !!!!! I made these tonight and they were sooo good ! Thank you so much for sharing the recipe !
Krista Stechman
I also made a few batches of these tonight! So glad you liked them!
Angel
Very delicious!
admin
Glad you liked them!
Meredith
I did a 1.5x batch of this in a 9x13 for a birthday get together and it was a big hit! Definitely a yummy recipe- thanks!
admin
That's a great idea! So happy you tried it, thanks so much!
Karyn Rea
Can’t wait to try these. They look delicious! Do you ever provide weight amounts in your recipes?
admin
Thank you so much! I do not usually provide weights unless that is the way I make the particular recipe. I hope you enjoy them if you try them!
Karyn Rea
Can’t wait to try these. They look delicious! Do you ever provide weight amounts?
Layla
SO YUMMY
admin
So glad you loved them! Thank you so much for making them and leaving a review, I really appreciate it!
Michelle
Oh my goodness. These are amazing. The browned butter frosting is perfect. I think next time I make them I will put some walnuts in. This is my new favorite dessert!
admin
Hi Michelle! I'm so glad you loved them, thank you so much for sharing and leaving a rating. I really appreciate it! Definitely love them with walnuts 🙂