Why are my layers muddy?

Too much stirring remixes the batters and makes them the same color. Use a butter knife to draw one figure-eight pattern across the bottom of the pan, scraping batter off the bottom. Do not draw another figure-eight pattern if you cannot see streaks in the batter.

Why did the banana topping lose its crisp sugar?

Burned sugar on fruit draws moisture out of the fruit. Put round banana slices on top of each square and add burned sugar just before eating to prevent the sugar from drawing moisture out of the fruit.

Can I make these ahead?

You can chill the whole sheet of baked bread in the refrigerator for 30 minutes to make it easier to slice.

How should I store banana bread brownies?

Let the squares sit at room temperature to avoid condensation in the container. Cover unwrapped squares with a paper towel and store them in a tightly sealed container to keep them fresh at room temperature. Unrefrigerated squares can be stored for up to three days. I suggest storing refrigerated squares for up to one week and topping each with a caramelized banana coin before serving.

Can I freeze the squares?

Yes, you can wrap each ungarnished square individually in plastic wrap and foil. The squares can be stored frozen for up to three months and thawed overnight in the refrigerator.

Banana Bread Brownies: Marbled Chocolate Dessert

By Mason BrooksOct 12, 2026

Cook

45 min

Total

45 min

Servings

Level

Medium

Jump to recipe

Whipping sugar and eggs into melted butter makes a crisp, glossy topping for banana bread brownies filled with thick chocolate batter. I make banana bread brownies to use ripe bananas when I can't make banana bread (I like the swirl).

Banana Bread Brownies: Marbled Chocolate Dessert

Bake in an 8×8-inch light-colored metal pan lined with parchment paper that hangs over two sides of the pan to avoid overbrowning of the bananas, which can occur when using a glass pan. Spread the chocolate batter into the corners of the pan using an offset spatula. This step will help ensure an even base for the banana batter before the batters are swirled together.

Stick a toothpick into the center of the brownie to see moist, fudgy crumbs. Do not bake until a toothpick inserted into the center comes out clean, as this will cause the brownie layer to dry out. If crumbs cling to a toothpick, the brownie is ready to be cut once cooled. Chocolate chips will stay visible as small dark pools on the marbled surface.

For serving, I use a white ceramic plate to highlight the marbled texture of the square and add a caramelized banana slice to the plate right before serving. Suggested beverage pairings include a glass of cold whole milk or a robust shot of hot espresso.

Why you'll love this recipe

Beat the butter and sugar for two minutes, then add the eggs gradually to form a crispy layer.
An 8-inch by 8-inch light metal pan is recommended to prepare thicker crusts without overbaking the edges.
A figure-eight pattern has dark and banana-colored streaks within each square, Other patterns are present in other squares.
Remove the brownie from the oven if a toothpick inserted into it comes out with moist crumbs or when the brownie layer still feels fudgy.
Press chocolate chips into the unbaked dough, Chocolate chips will stay dotted across the top of the baked item.
Parchment covering both sides makes it easy to remove the cooled slab to cut into squares.

Instructions

Preheat the oven to 350°F (175°C).

Line an 8×8-inch light-colored metal baking pan with parchment paper, leaving an overhang on two sides.

Whisk the melted butter and granulated sugar for about two full minutes in a large glass mixing bowl.

Whisk in the eggs one at a time until the mixture is pale and thicker.

Fold in the melted dark chocolate and vanilla extract until smooth.

Sift the cocoa powder, all-purpose flour, and kosher salt over the wet mixture.

Fold the dry ingredients in with a rubber spatula until just combined.

Spread the brownie batter evenly in the prepared pan with an offset spatula.

Mash the overripe bananas in a separate medium bowl until nearly liquid with no large lumps.

Whisk the melted butter, granulated sugar, egg, and vanilla extract into the mashed bananas.

Sprinkle the all-purpose flour, baking soda, and kosher salt over the banana mixture.

Fold the banana batter until no dry flour streaks remain.

Spoon dollops of banana bread batter over the chocolate batter.

Drag a butter knife through both batters in one continuous figure-eight motion, scraping to the bottom of the pan.

Scatter the semi-sweet chocolate chips over the surface and press them gently into the batter.

Bake for 40 to 45 minutes, until a toothpick inserted in the center comes out with moist, fudgy crumbs attached.

Cool the bake entirely in the pan.

Cut the cooled slab into neat squares.

Place one thin banana round on each square.

Sprinkle the banana rounds with sugar.

Briefly torch the sugared banana rounds until caramelized.

FAQ

Cold eggs can make the melted butter curdle. Let the eggs sit at room temperature before using them. Add eggs one at a time to the batter and continue mixing to make the batter thicker and lighter.

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Desserts Vegetarian Baking

Banana Bread Brownies: Marbled Chocolate Dessert

Name: Banana Bread Brownies: Marbled Chocolate Dessert
Cook time: 45 min
Total time: 45 min
Yield: 16 squares
Ingredients: 1/2 cup unsalted butter (113 g, melted, for brownie batter); 1 cup granulated sugar (200 g, for brownie batter); 2 large eggs (100 g, room temperature, for brownie batter); 1/2 cup unsweetened cocoa powder (45 g); 1/2 cup all-purpose flour (60 g, for brownie batter); 2 oz dark chocolate (56 g, melted); 1/4 tsp kosher salt (1.5 g, for brownie batter); vanilla extract (amount not specified, used in both batters); 3/4 cup overripe bananas (150 g, mashed); 1/4 cup unsalted butter (56 g, melted, for banana bread batter); 1/2 cup granulated sugar (100 g, for banana bread batter); 1 large egg (50 g, for banana bread batter); 3/4 cup all-purpose flour (90 g, for banana bread batter); 1/2 tsp baking soda (2.5 g); kosher salt (for banana bread batter, amount not specified); 1/2 cup semi-sweet chocolate chips (85 g); 1 firm banana (118 g, sliced into 16 thin rounds); 1 tbsp granulated sugar (12 g, for banana garnish)

By Mason BrooksOct 12, 2026

Cook

45 min

Total

45 min

Servings

Level

Medium

Jump to recipe

Why you'll love this recipe

Beat the butter and sugar for two minutes, then add the eggs gradually to form a crispy layer.
An 8-inch by 8-inch light metal pan is recommended to prepare thicker crusts without overbaking the edges.
A figure-eight pattern has dark and banana-colored streaks within each square, Other patterns are present in other squares.
Remove the brownie from the oven if a toothpick inserted into it comes out with moist crumbs or when the brownie layer still feels fudgy.
Press chocolate chips into the unbaked dough, Chocolate chips will stay dotted across the top of the baked item.
Parchment covering both sides makes it easy to remove the cooled slab to cut into squares.

Ingredients

Servings16

•½ cup unsalted butter (113 g, melted, for brownie batter)
•1 cup granulated sugar (200 g, for brownie batter)
•2 large eggs (100 g, room temperature, for brownie batter)
•½ cup unsweetened cocoa powder (45 g)
•½ cup all-purpose flour (60 g, for brownie batter)
•2 oz dark chocolate (56 g, melted)
•¼ tsp kosher salt (1.5 g, for brownie batter)
•vanilla extract (amount not specified, used in both batters)
•¾ cup overripe bananas (150 g, mashed)
•¼ cup unsalted butter (56 g, melted, for banana bread batter)
•½ cup granulated sugar (100 g, for banana bread batter)
•1 large egg (50 g, for banana bread batter)
•¾ cup all-purpose flour (90 g, for banana bread batter)
•½ tsp baking soda (2.5 g)
•kosher salt (for banana bread batter, amount not specified)
•½ cup semi-sweet chocolate chips (85 g)
•1 firm banana (118 g, sliced into 16 thin rounds)
•1 tbsp granulated sugar (12 g, for banana garnish)

Instructions

1
Preheat the oven to 350°F (175°C).
2
Line an 8×8-inch light-colored metal baking pan with parchment paper, leaving an overhang on two sides.
3
Whisk the melted butter and granulated sugar for about two full minutes in a large glass mixing bowl.
4
Whisk in the eggs one at a time until the mixture is pale and thicker.
5
Fold in the melted dark chocolate and vanilla extract until smooth.
6
Sift the cocoa powder, all-purpose flour, and kosher salt over the wet mixture.
7
Fold the dry ingredients in with a rubber spatula until just combined.
8
Spread the brownie batter evenly in the prepared pan with an offset spatula.
9
Mash the overripe bananas in a separate medium bowl until nearly liquid with no large lumps.
10
Whisk the melted butter, granulated sugar, egg, and vanilla extract into the mashed bananas.
11
Sprinkle the all-purpose flour, baking soda, and kosher salt over the banana mixture.
12
Fold the banana batter until no dry flour streaks remain.
13
Spoon dollops of banana bread batter over the chocolate batter.
14
Drag a butter knife through both batters in one continuous figure-eight motion, scraping to the bottom of the pan.
15
Scatter the semi-sweet chocolate chips over the surface and press them gently into the batter.
16
Bake for 40 to 45 minutes, until a toothpick inserted in the center comes out with moist, fudgy crumbs attached.
17
Cool the bake entirely in the pan.
18
Cut the cooled slab into neat squares.
19
Place one thin banana round on each square.
20
Sprinkle the banana rounds with sugar.
21
Briefly torch the sugared banana rounds until caramelized.

FAQ

Cold eggs can make the melted butter curdle. Let the eggs sit at room temperature before using them. Add eggs one at a time to the batter and continue mixing to make the batter thicker and lighter.