These fudgy, swirled Banana Bread Brownies bring together rich chocolate brownie batter and sweet banana bread in every bite. I started making these after I had a few overly ripe bananas sitting on my counter and a serious craving for brownies, and honestly, it's become one of my favorite ways to use up those spotty bananas. The chocolate swirls through the banana batter in the prettiest marbled pattern, and the whole thing bakes up soft and moist with crispy edges.

If you love quick dessert bars with bananas, this easy recipe is ready in under an hour with simple pantry ingredients. You might also enjoy these Marshmallow Brownies or this Peanut Butter Banana Cake for more creative twists on classic treats.
What Makes These Banana Bread Brownies Special
This Banana Bread Brownies is a true hybrid dessert. You're not just adding banana to brownie batter or swirling chocolate into banana bread. You're making one base batter, then splitting it into two completely different batters, one rich and chocolatey, the other light and banana-forward. When you swirl them together and bake, you get the best of both worlds in every single square.
The Banana Bread Brownies portion stays tender and almost cake-like, while the brownie batter adds deep chocolate flavor and those slightly crisp edges we all love. It's a banana chocolate dessert that feels special enough for a party but easy enough to whip up on a weeknight.
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Banana Bread Brownies Ingredients
Here's everything you'll need to make these chocolate Banana Bread Brownies.
See Recipe Card Below This Post For Ingredient Quantities
For the Batter:
- Unsalted butter : Adds richness and moisture to both batters. Make sure it's softened so it mixes smoothly with the sugars.
- Granulated sugar : Sweetens the batter and helps create a slightly crisp top.
- Brown sugar : Brings a hint of molasses flavor and extra moisture, which keeps the brownies soft.
- Large eggs : Bind everything together and add structure. Room temperature eggs blend in more easily.
- Vanilla extract : Enhances both the chocolate and banana flavors without overpowering either one.
- All-purpose flour : Forms the base structure. Don't overmix once you add it, or the brownies can turn out tough.
- Salt (½ teaspoon): Balances the sweetness and brings out the chocolate flavor.
For the Banana Bread Batter:
- Over-ripe mashed bananas : The star of the banana bread portion. The browner and spottier your bananas, the sweeter and more flavorful your batter will be.
- Baking powder : Gives the banana bread batter a little lift so it stays light and fluffy.
For the Brownie Batter:
- Unsweetened cocoa powder : Provides deep, rich chocolate flavor. Use good-quality cocoa for the best results.
- Semisweet chocolate chips : Melts into pockets of gooey chocolate throughout the brownie batter.
- Semisweet chocolate chips for topping : Sprinkled on top before baking for extra chocolate in every bite.
How to Make Banana Bread Brownies
Here's how to make the best Banana Bread Brownies from scratch.
Preheat oven: Set your oven to 350°F (175°C). Line a 9 x 9 x 2-inch square baking pan with parchment paper, leaving a little overhang on the sides so you can lift the brownies out easily later.
Prepare the batter: In a large bowl, whisk together ¾ cup softened unsalted butter, 1 cup granulated sugar, and ½ cup brown sugar until the mixture is smooth and creamy. Add 3 large eggs and 2 teaspoons vanilla extract, whisking until everything is well combined and slightly fluffy.
Mix dry ingredients: Stir in ¾ cup all-purpose flour and ½ teaspoon salt until just combined. Don't overmix, or you'll end up with dense brownies. A few streaks of flour are okay.
Prepare banana bread batter: In a medium bowl, mash 1 cup over-ripe bananas with a fork until mostly smooth. Sprinkle ½ teaspoon baking powder over the mashed bananas and mix well. Pour half of the base batter into the banana mixture and stir until fully combined. Set this bowl aside.
Prepare brownie batter: To the remaining half of the batter still in the large bowl, add ½ cup unsweetened cocoa powder and ¾ cup semisweet chocolate chips. Stir gently until the cocoa is fully mixed in and the batter turns a rich, dark brown.

Assemble the dessert: Spoon half of the brownie batter into your prepared pan. It doesn't need to cover the entire bottom, just drop it in random spoonfuls. Pour all of the banana bread mixture on top, spreading it gently. Then drop spoonfuls of the remaining brownie batter over the banana layer. Use a butter knife to gently swirl the two batters together, creating a marbled pattern. Don't overmix, you want to see distinct swirls of banana and chocolate.

Add finishing touch: Sprinkle 2 tablespoons semisweet chocolate chips evenly over the top of the batter.
Bake: Bake for 40 to 45 minutes, until the edges look set and a toothpick inserted into the center comes out clean with just a few moist crumbs. The center might look slightly soft, but it will firm up as it cools.
Cool: Let the pan cool completely on a wire rack before slicing into 16 squares. If you try to cut them while they're warm, they'll fall apart.
Substitutions and Variations
Banana: You can use frozen bananas, just thaw and drain them first. Fresh bananas work, but overripe ones give you the best flavor.
Butter: Swap with coconut oil for a dairy-free version, though the flavor will be slightly different.
Chocolate chips: Use dark chocolate chips, milk chocolate chips, or even white chocolate chips depending on your preference. You can also add chopped walnuts or pecans for crunch.
Cocoa powder: Dutch-process cocoa will give you a smoother, slightly less acidic chocolate flavor.
Gluten-free option: Use a 1:1 gluten-free flour blend in place of all-purpose flour.
Vegan version: Replace the eggs with flax eggs (3 tablespoons ground flaxseed mixed with 9 tablespoons water, let sit for 5 minutes), use vegan butter, and choose dairy-free chocolate chips.
Equipment For Banana Bread Brownies
- Electric hand mixer or whisk: Makes creaming the butter and sugars much easier, though a strong arm and a whisk will work too.
- 9 x 9 x 2-inch square baking pan: The perfect size for thick, bakery-style brownies. If you use a larger pan, they'll bake faster and turn out thinner.
- Parchment paper: Lining your pan makes cleanup easy and helps you lift the brownies out in one piece.
- Large and medium mixing bowls: You'll need both to keep the two batters separate before swirling.
- Knife for swirling batter: A butter knife or offset spatula works great for creating those pretty swirls.
Storage Tips For Banana Bread Brownies
Room temperature: Store the Banana Bread Brownies in an airtight container at room temperature for up to 3 days. They stay moist and soft thanks to the banana.
Refrigerator: Keep them in the fridge for up to 5 days if you want them to last longer. Let them come to room temperature before serving, or warm them in the microwave for 10 to 15 seconds.
Freezer: Wrap individual squares tightly in plastic wrap, then place them in a freezer-safe bag or container. Freeze for up to 3 months. Thaw at room temperature or warm in the microwave.
Make-ahead: You can make the batter the night before, cover both bowls, and refrigerate. Let them come to room temperature before assembling and baking.
Serving Suggestions
Serve these Banana Bread Brownies dessert warm with a scoop of vanilla ice cream melting over the top. The contrast between the warm brownie and cold ice cream is perfect.
Drizzle with salted caramel sauce or chocolate ganache for an extra-special dessert. A sprinkle of flaky sea salt on top right before serving brings out the chocolate flavor even more.
Pair with a cold glass of milk or a hot cup of coffee. The rich chocolate and sweet banana balance beautifully with both.
Pack them in lunchboxes or bring them to potlucks. They travel well and everyone loves the combo of flavors. If you're looking for more crowd-pleasers, try these S'mores Brownie Cupcakes or Biscoff Cupcakes.
Expert Tips
Use very ripe bananas. The more brown spots, the sweeter and more flavorful your banana bread batter will be. If your bananas aren't ripe enough, stick them in a 300°F oven for 15 minutes to speed up the process.
Don't overmix the batter. Once you add the flour, stir just until you don't see any dry streaks. Overmixing creates tough, dense Banana Bread Brownies.
Swirl gently. You want to see distinct ribbons of banana and chocolate, not a fully blended batter. Three or four swirls with your knife is enough.
Let them cool completely. I know it's hard to wait, but warm Banana Bread Brownies are nearly impossible to cut cleanly. Let the pan cool for at least an hour.
Line your pan with parchment. This makes lifting the whole block of brownies out so much easier. You can cut perfect squares without fighting with stuck edges.
Check for doneness carefully. A toothpick should come out with a few moist crumbs, not wet batter. If it comes out completely clean, you might have overbaked them.
Add mix-ins if you want. Chopped walnuts, shredded coconut, or even a swirl of peanut butter all work beautifully in this Banana Bread Brownies.
FAQ
What is the number one mistake made when making banana bread?
Overmixing the batter. Once you add the flour, stir just until combined. If you mix too much, the gluten develops and your banana bread (or in this case, banana brownies) turns out dense and tough instead of soft and tender. My mom always said to stop stirring the second you stop seeing flour streaks.
What is the secret to the best banana bread?
Overripe bananas. The browner and spottier they are, the sweeter and more flavorful your banana bread will be. If your bananas are still yellow, let them sit on the counter for a few more days, or pop them in a low oven for 15 minutes to ripen them faster. Also, don't skimp on the vanilla extract.
What is the secret ingredient in Grandma's Signature brownie recipe?
A pinch of espresso powder or a teaspoon of instant coffee. It doesn't make the brownies taste like coffee, but it deepens the chocolate flavor and makes everything taste richer. Some bakers also swear by a little bit of brown sugar instead of all white sugar for extra moisture and chewiness.
How long do you bake Banana Bread Brownies for?
Bake these moist Banana Bread Brownies for 40 to 45 minutes at 350°F. You'll know they're done when the edges look set and a toothpick inserted into the center comes out with just a few moist crumbs. If the toothpick comes out completely clean, they might be slightly overbaked, so check a minute or two early.
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Pairing
These are my favorite dishes to serve with Banana Bread Brownies

Banana Bread Brownies
Ingredients
- ¾ cup unsalted butter room temperature
- 1 cup granulated sugar white sugar
- ½ cup brown sugar light or dark
- 3 large eggs beaten
- 2 teaspoons vanilla extract pure vanilla extract
- ¾ cup all-purpose flour for best results use unbleached flour
- ½ teaspoon salt fine salt
- 1 cup over-ripe mashed bananas about 2 medium bananas mashed well
- ½ teaspoon baking powder for leavening the banana bread portion
- ½ cup unsweetened cocoa powder dark cocoa powder
- ¾ cup semisweet chocolate chips for the brownie batter
- 2 tablespoons semisweet chocolate chips for sprinkling on top
Instructions
- Preheat the oven to 350°F (175°C) and line a 9x9-inch square baking pan with parchment paper.
- In a large bowl, use an electric mixer or whisk to beat ¾ cup unsalted butter, 1 cup granulated sugar, and ½ cup brown sugar together until smooth. Add 3 large eggs and 2 teaspoons vanilla extract and mix until fully combined.
- Stir in ¾ cup all-purpose flour and ½ teaspoon salt, mixing just until combined.
- In a separate medium bowl, mash 1 cup over-ripe mashed bananas and sprinkle ½ teaspoon baking powder on top. Stir to combine, then add half of the prepared batter into the banana mixture and stir to combine. Set aside.
- Add ½ cup unsweetened cocoa powder and ¾ cup semisweet chocolate chips into the remaining half of the batter mixture. Stir to combine.
- Dollop spoonfuls of about half of the brownie batter into the prepared pan. It doesn't need to cover the bottom completely. Pour the banana bread mixture over the brownie mixture, spreading it evenly. Drop spoonfuls of the remaining brownie batter on top, then use a knife to gently swirl the two mixtures together.
- Sprinkle 2 tablespoons semisweet chocolate chips on top before baking.
- Bake for 40 to 45 minutes or until a toothpick inserted into the center comes out clean with just a few crumbs attached. Let cool completely before slicing into squares.













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