Peanut Butter Banana Brownies

We always end up with overripe bananas in our household, so I wanted to find a way to incorporate those into a baked treat that satisfies chocolate cravings. Hence the idea for these peanut butter banana brownies was born!

These flavors go SO well together: the fudgy chocolate brownie (with pools of melty chocolate chips), the sweet banana, and the salty peanut butter swirl on top.

Banana Brownies with Peanut Butter Swirl

Bananas are a popular addition to baked goods, especially as a way to add sweetness naturally. They’re delicious in banana bread, cakes, pies, and cookies. But for some reason, I hadn’t tried them in brownies until recently.

It makes sense that bananas would be good in brownies, though – they’re sweet, pair well with chocolate, and help keep the brownies nice and fudgy. And with the addition of the peanut butter swirl here, they’re absolutely irresistible.

I shared these with some family that was in town for a taste test, and they were a big hit!

Recipe Ingredients

To make these banana brownies, you’ll need:

• ripe bananas: You’ll need 2 small-to-medium bananas here. Very ripe or overripe bananas are best, as they’ll be easier to mash and they’ll make the brownies taste sweeter. (If your bananas are pretty brown/spotty, transfer them to the fridge in an airtight bag so they’ll keep longer until you’re ready to bake.)
• all-purpose flour
• butter: Because we’re using ripe bananas in these brownies, we don’t need as much butter (compared to typical brownies). But we’re still using some to make sure they’re still plenty rich and moist.
• sugar: Again, thanks to the bananas, we don’t need as much sugar as typical brownies would call for. A combination of white and brown sugar gives just the right amount of sweetness, and the brown sugar enhances the fudgy texture.
• eggs: For structure and rise. Make sure they’re at room temp!
• cocoa powder: Unsweetened cocoa powder gives the brownies that rich, chocolatey flavor we know and love!
• vanilla extract
• chocolate chips: I added chocolate chips for even more chocolatey goodness. Any kind should work: dark, semisweet, or milk chocolate.
• peanut butter: For the delicious, slightly salty swirl on top! You can skip this if you want – it shouldn’t affect the actual baking of the brownies. (I haven’t tested these with natural peanut butter, but I think it should work as long as you stir it well first. Let me know if you try it!)
• baking powder
• salt

If you have extra overripe bananas, try these hazelnut banana bread bars! Or, for more peanut butter goodness, try these peanut butter chocolate chip cookie bars or these flourless peanut butter cookies.

How to Make Banana Brownies

In terms of the baking process, these are pretty similar to your standard brownies, with the exception of adding mashed banana and the peanut butter swirl on top.

You start by combining all the dry ingredients (including the cocoa powder) in a medium-sized bowl and whisking them together. Set aside for now.

In a separate large mixing bowl, combine hot melted butter with the sugars (white and brown) and whisk well. Add the eggs, mashed banana, and vanilla extract, then whisk again until well-mixed.

Then, sift in the mixed dry ingredients (this helps prevent clumps) and stir with a rubber spatula until almost combined.

Pour in chocolate chips and fold them in with the spatula, until there are no more flour streaks.

Pour the mixture into an 8x8in square baking dish lined with parchment paper. Next, it’s time to create the peanut butter swirl!

Add a Peanut Butter Swirl

Microwave peanut butter in a microwave-safe bowl in 30-second increments on 50% power, until smooth and drippy. Dollop spoonfuls over different spots of your brownie batter.

Then, using a butter knife, swirl through the dollops (as if you’re drawing wide squiggles), creating a swirled pattern. Try not to press the peanut butter down too deep into the batter.

Then, bake at 350 degrees Fahrenheit for 25-30 minutes. Check with a toothpick – it should come out with just a few fudgy crumbs.

Allow the brownies to cool, then remove them from the baking pan (using the parchment paper) and slice with a sharp knife.

Tips for Slicing Brownies

If you want to make cleaner slices, be sure to let your brownies cool completely first. Running your knife under hot water (and drying it) first will also help make the slices cleaner.

Lining your baking pan with parchment paper is also essential, as it allows you to remove the uncut brownies from the pan cleanly. Once they’re out of the pan, they’re much easier to slice.

Storage Tips

Store leftover brownies in an airtight container on the counter (at room temperature) for up to 3 days.

Peanut Butter Banana Brownie Toppings & Mix-Ins

Here are a few different ways to change up this brownie recipe:

• Add chopped nuts or shredded coconut to the batter
• Use another nut butter, like almond butter, for the swirl on top instead
• Or, add a Nutella or Biscoff spread swirl
• Top with chopped peanuts

This is definitely my new go-to brownie recipe – especially when I have browning bananas waiting the counter, practically begging to be used. In fact, it might be time to whip up another batch right now. 🙂

If you try these peanut butter banana brownies, I’d love if you shared your thoughts with a rating and comment below!

More delicious baked desserts:

• Raspberry Almond Blondies
• Iced Lemon Mascarpone Cookies
• Almond Butter Cookie Bars
• White Chocolate Matcha Brownies
• Blueberry Walnut Blondie Bars
• Mini Egg Brownies with Coconut