Why Make These Brownies? This is the best of both worlds—the dense, fudgy texture of a brownie meets the sweet, comforting flavor of banana bread. These bars are impossibly moist, packed with ripe banana flavor, and swirled with chocolate chips or a glossy brown butter frosting. They are perfect for using up overripe bananas, and they come together in one bowl with no mixer required. Whether you serve them as an after-school snack, a lunchbox treat, or a potluck dessert, these banana bread brownies will disappear faster than you can say “seconds.”
Ingredients
For the brownies: one and a half cups mashed ripe bananas (about three large bananas), half cup unsalted butter (melted and slightly cooled), one cup packed brown sugar (light or dark), one large egg (room temperature), one teaspoon vanilla extract, one cup all-purpose flour, one teaspoon baking soda, one quarter teaspoon salt, and one cup semi-sweet chocolate chips (or chopped walnuts).
For the brown butter frosting (optional but incredible): half cup unsalted butter, two cups powdered sugar (sifted), one teaspoon vanilla extract, and two to three tablespoons milk or heavy cream.
Equipment Needed
An 8×8 inch or 9×9 inch square baking pan, parchment paper, a large mixing bowl, a whisk or fork, a rubber spatula, a small saucepan for the frosting (if making), and a toothpick for testing.
Method
Preheat your oven to 175°C (350°F). Line an 8×8 inch square baking pan with parchment paper, leaving some overhang on two sides for easy removal. Lightly grease the paper or the pan with cooking spray.
In a large mixing bowl, mash the ripe bananas with a fork until smooth with only a few small lumps. You should have about one and a half cups of banana puree.
Add the melted butter, brown sugar, egg, and vanilla extract to the mashed bananas. Whisk or stir until everything is well combined and smooth.
Sprinkle the flour, baking soda, and salt over the wet mixture. Stir gently with a rubber spatula until just combined. Do not overmix—the batter should be thick and slightly lumpy.
Fold in the chocolate chips (or walnuts) with the spatula, reserving a handful to sprinkle on top if desired.
Pour the batter into the prepared baking pan and spread it evenly with a spatula. Sprinkle the reserved chocolate chips over the top.
Bake for twenty five to thirty minutes, until the edges are set and a toothpick inserted into the center comes out clean or with just a few moist crumbs. The top should be golden brown and slightly cracked.
Let the brownies cool completely in the pan on a wire rack before frosting or slicing. If you skip the frosting, you can slice them while they are still warm.
If making the brown butter frosting, prepare it while the brownies cool. In a small saucepan over medium heat, melt the butter. Continue cooking, swirling the pan occasionally, until the butter turns a deep amber color and smells nutty and toasty, about five to seven minutes. Watch carefully—brown butter can go from perfect to burnt in seconds. Remove from heat immediately.
Pour the browned butter into a mixing bowl, scraping all the dark bits from the bottom of the pan. Let it cool for ten to fifteen minutes until it is no longer hot but still soft.
Add the powdered sugar, vanilla extract, and two tablespoons of milk to the browned butter. Beat with a whisk or electric mixer until smooth. Add more milk one teaspoon at a time if the frosting is too thick—it should be thick but spreadable.
Spread the brown butter frosting evenly over the cooled brownies. Let the frosting set for about fifteen minutes before slicing.
Use the parchment overhang to lift the slab from the pan. Cut into nine or sixteen squares.
Storage
Store frosted brownies in an airtight container at room temperature for up to three days, or in the refrigerator for up to one week (bring to room temperature before serving). Unfrosted brownies can be stored at room temperature for up to four days or frozen for up to three months. Thaw at room temperature, then frost or serve as is.
Variations
For a chocolate banana bread brownie, add one quarter cup of unsweetened cocoa powder to the dry ingredients and reduce the flour to three quarters cup. For a peanut butter swirl version, drop spoonfuls of creamy peanut butter over the batter and swirl with a knife before baking. For a cream cheese swirl version, beat four ounces of softened cream cheese with one quarter cup of sugar and one egg yolk, then swirl into the batter. For a gluten-free version, use a cup-for-cup gluten-free flour blend. For a dairy-free version, use melted coconut oil instead of butter and dairy-free chocolate chips. For a nutty version, use chopped walnuts or pecans instead of chocolate chips, or use half chocolate chips and half nuts. For a streusel topping version, mix together one quarter cup of flour, one quarter cup of brown sugar, two tablespoons of cold butter, and one teaspoon of cinnamon, then crumble over the batter before baking.
Serving Suggestions
Serve as an afternoon snack with a glass of cold milk. Pack in lunchboxes for a sweet treat. Serve warm with a scoop of vanilla ice cream for dessert. Dust with powdered sugar for a pretty presentation. Drizzle with caramel sauce or chocolate syrup. Serve alongside coffee or tea for an afternoon pick-me-up. Top with a dollop of whipped cream and a sprinkle of cinnamon.
Tips for Best Results
Use very ripe bananas with brown spots. The riper the banana, the sweeter and more intense the banana flavor. Black-spotted bananas are ideal. If your bananas are not ripe enough, place them in a 150°C (300°F) oven for fifteen minutes until the skins turn black, then let them cool before mashing.
Mash the bananas thoroughly. Lumpy bananas will create pockets of unincorporated fruit that can make the brownies gummy. Mash with a fork until mostly smooth, with only a few small lumps remaining. A potato masher works well for larger batches.
Do not overmix the batter. Banana bread brownies are supposed to be dense and fudgy, not tough. Overmixing develops gluten and creates a rubbery texture. Stir just until the flour disappears into the wet ingredients—a few small lumps are fine.
Use brown sugar for deeper flavor. Brown sugar adds molasses notes that complement the banana and make the brownies more moist than granulated sugar. Dark brown sugar gives an even richer, more caramel-like flavor.
Do not overbake. The brownies are done when a toothpick inserted into the center comes out clean or with a few moist crumbs. Overbaking will dry them out. Start checking at twenty five minutes.
Make the brown butter frosting for a spectacular finish. Brown butter adds a nutty, toasty depth that is incredible with banana. The frosting takes ten minutes and elevates these brownies from great to unforgettable. If you are short on time, a simple dusting of powdered sugar works well too.
Let the brownies cool completely before frosting. Warm brownies will melt the frosting into a thin glaze. For the classic thick, spreadable frosting, wait until the brownies are at room temperature.
Cut with a sharp knife, wiping the blade clean between cuts. The brownies are moist and the frosting can be sticky. A clean, sharp knife gives you neat, bakery-style squares. For the cleanest cuts, refrigerate the frosted brownies for thirty minutes before slicing.
Make a double batch. These brownies freeze beautifully. Make two batches in two 8×8 pans. Serve one and freeze the other for later. Thaw at room temperature, then frost if desired.
Serve slightly warm for the ultimate experience. If you have time, warm individual brownies in the microwave for ten to fifteen seconds before serving. The chocolate chips become molten and the banana flavor intensifies. A scoop of vanilla ice cream on top is not optional—it is mandatory.