Last week I had three ripe bananas sitting on my counter, and normally that means I’m making my go to banana pancakes. They’re one of those recipes I make all the time when I have bananas that need to be used.

But this week, I wanted to try something new.

I started looking through what I already had in my kitchen and decided to make these brown butter banana bars, and I am so glad I did.

The best part is that I already had everything I needed in my pantry, and I’m guessing you probably do too. There aren’t any unusual ingredients or anything you need to make a special trip to the grocery store for. They’re also surprisingly easy to make.

The bars themselves are incredibly soft and moist with lots of banana and cinnamon flavor, but the part that absolutely makes this recipe is the brown butter frosting.

I made a few changes to make these exactly how I like them. I use a full tablespoon of cinnamon because I really want that warm cinnamon flavor to come through, and I leave the nutmeg out completely.

I also use one cup less powdered sugar in the frosting. Three cups is plenty sweet for me, and it gives the frosting the most incredible consistency.

We’ll get to that because I need to talk about this frosting.

The Brown Butter Is Everything

If there is one ingredient I wouldn’t skimp on for this recipe, it’s the butter.
I like using a good grass fed butter. You’ll notice right away that grass fed butter has a much richer, deeper yellow color compared with a really pale butter. I love using it here because butter isn’t just another ingredient in this frosting. It’s the main flavor.

Once you brown it, it gets even better.

Browning butter might sound fancy if you’ve never done it before, but it’s actually really simple. You’re basically cooking the butter just long enough for the milk solids to toast.

As the butter melts, it will start to foam. Keep stirring and watching the bottom of the pan. Eventually you’ll see little golden brown bits starting to appear.

I don’t really go by time when I’m browning butter. I watch the color and smell it.

The butter will deepen from that beautiful dark yellow into a golden brown, and you’ll start smelling this rich, nutty, almost caramel like aroma.

That’s what you want.

Just don’t walk away from it. Once butter starts browning, it can go from beautifully toasted to burnt pretty quickly.

The Frosting Is What Makes These

The best way I can describe the brown butter frosting is this:
If frosting and the icing on a glazed doughnut had a baby, this would be it.
It has the BEST texture.

When you first pour it over the warm banana bars, it’s soft and smooth and almost melts into the top of the cake.

Then something magical happens as it sits.

The very top starts to set and forms this delicate little shell, almost like the glaze on a doughnut. But underneath that thin layer, the frosting stays soft and creamy.

So when you bite into it, you get that slight glazed texture on top, then the soft brown butter frosting underneath, and finally the super moist banana cake.

It’s so good.

I really think using one cup less powdered sugar is part of what gives me the texture I love. I don’t want a thick, fluffy buttercream sitting on top of these. I want the frosting to pour over the cake, settle into it, and develop that beautiful glazed finish as it sits.

After eating one of these bars, I immediately started thinking about all the other things I could put this frosting on.

Cinnamon rolls, pumpkin cake, apple cake, doughnuts. I could keep going.

The frosting almost deserves its own recipe.

What You’ll Need

For the Banana Bars
1¾ cups (262 g) gluten free measure for measure flour
1 teaspoon baking soda
1 teaspoon baking powder
¾ teaspoon kosher salt
1 tablespoon ground cinnamon
1 cup (230 g) mashed very ripe banana, about 2 to 3 bananas
2 tablespoons milk
2 teaspoons vanilla extract
3 large eggs
¾ cup (150 g) granulated sugar
½ cup (106 g) brown sugar
⅔ cup (160 ml) neutral oil

For the Brown Butter Frosting
½ cup (113 g) grass fed butter
⅓ cup (80 ml) milk
3 cups (360 g) powdered sugar
1 teaspoon vanilla extract
Pinch of kosher salt
Finely chopped walnuts, optional
Fresh banana slices for the top, optional

How I Make the Banana Bars

Preheat your oven to 375°F and grease a 10 by 15 inch jelly roll pan.

In a large bowl, whisk together the gluten free flour, baking soda, baking powder, kosher salt, and one full tablespoon of cinnamon.

In a separate bowl, mash your ripe bananas until they’re nice and soft. Mix in the milk and vanilla and set that aside.

Add the eggs, granulated sugar, and brown sugar to your mixer. Beat everything together for about 2 to 3 minutes, until the mixture becomes lighter in color and looks nice and fluffy.

Turn your mixer to low and slowly drizzle in the oil.

Next, alternate adding the dry ingredients and banana mixture. Keep your mixer low and mix only until everything has come together. Once you don’t see any dry flour remaining, you’re done.

Pour the batter into your prepared pan and spread it into an even layer.
Bake at 375°F for about 25 to 30 minutes.

I like to start checking mine around the 25 minute mark. Insert a toothpick into the center, and when it comes out clean, they’re ready.

Take the pan out of the oven and let the bars sit for about 10 to 15 minutes.

You don’t want them completely cold when you add the frosting. I actually want them to still have a little warmth because I love how the frosting settles over the top.

Making the Brown Butter Frosting

While the banana bars are cooling, add your grass fed butter to a pan over medium low heat.

Let the butter melt and begin to foam, stirring frequently.

Keep watching the bottom of the pan. You’ll begin seeing little browned milk solids appearing as the butter deepens in color.

And remember, use your nose too.

Once it smells rich, toasted, and nutty and has reached that beautiful golden brown color, it’s ready.

Add the milk and bring everything to a gentle simmer, then remove the pan from the heat.

Whisk in 3 cups of powdered sugar, the vanilla, and a pinch of kosher salt until everything is smooth.

Then pour that warm brown butter frosting right over the warm banana bars.

Let it naturally settle over the cake and gently spread it out if you need to.

While the frosting is still soft, sprinkle chopped walnuts over the top. I also love adding fresh banana slices when I’m serving them.

Then give the frosting some time to sit.

As it cools, you’ll see that beautiful little glazed shell start to form over the top while the frosting underneath stays soft.

Once everything has cooled, cut the bars into big squares.

My Final Thoughts

I started this recipe because I had three ripe bananas on my counter and wanted something different from my usual banana pancakes.

Now I might actually be hoping for my bananas to turn brown.

These bars are soft, moist, full of banana and cinnamon, and they’re made with ingredients I almost always have sitting in my pantry.

But that brown butter frosting is what I’ll be thinking about.

It’s buttery and nutty, soft underneath with that delicate glazed shell on top, and somehow tastes like something that took way more effort than it actually did.

If you have a few ripe bananas sitting on your counter right now, make these instead of banana bread this time. 🤎