Description
Thick, fudgy bars that combine moist banana bread with rich chocolate brownies. This dessert mashup creates gorgeous marbled layers that are perfect for satisfying every craving at once.
Ingredients
2 large very ripe bananas, mashed (about 1 cup)
¼ cup unsalted butter, melted (for banana layer)
½ cup granulated sugar (for banana layer)
1 large egg (for banana layer)
1 teaspoon vanilla extract (for banana layer)
1 cup all-purpose flour (for banana layer)
½ teaspoon baking soda
¼ teaspoon salt (for banana layer)
¼ teaspoon ground cinnamon
1 box (18-20 oz) brownie mix, plus ingredients called for on box
OR ½ cup unsalted butter, melted (for brownie layer)
1 cup granulated sugar (for brownie layer)
2 large eggs (for brownie layer)
1 teaspoon vanilla extract (for brownie layer)
⅓ cup unsweetened cocoa powder
½ cup all-purpose flour (for brownie layer)
¼ teaspoon salt (for brownie layer)
¼ teaspoon baking powder
½ cup chocolate chips (optional)
Instructions
1. Preheat your oven to 350°F and line a 9×13-inch baking pan with parchment paper, leaving overhang on all sides. Lightly grease the parchment with butter or cooking spray.
2. In a medium bowl, mash the very ripe bananas with a fork until mostly smooth. Add the melted butter, sugar, egg, and vanilla extract, stirring until smooth. Add the flour, baking soda, salt, and cinnamon, folding gently just until no dry flour streaks remain.
3. If using boxed brownie mix, prepare according to package directions. If making from scratch: In a separate bowl, whisk together the melted butter, sugar, eggs, and vanilla until smooth. Add the cocoa powder, flour, salt, and baking powder, stirring just until combined. Fold in chocolate chips if using.
4. Pour the banana bread batter into your prepared pan and spread it evenly across the bottom in a thin layer. Pour the brownie batter over the banana bread layer, spreading it gently and evenly to cover.
5. Use a butter knife or skewer to swirl the two batters together with gentle figure-eight or zigzag motions. Just 5-6 swirls create beautiful marbling – don’t overmix.
6. Bake for 35-40 minutes, until the edges are set and pulling away slightly from the pan, and a toothpick inserted into the center comes out with a few moist crumbs. The top should look set but still slightly soft.
7. Let the bars cool completely in the pan on a wire rack for at least 2 hours. Use the parchment overhang to lift the entire slab out of the pan, then cut into squares with a sharp knife, wiping it clean between cuts.
Notes
Use very ripe bananas with lots of brown spots or black peels for best flavor.
Don’t overbake – bars should look slightly underdone in center when removed from oven.
Cool completely before cutting – this takes at least 2 hours and is crucial for clean cuts.
Don’t over-swirl the batters – just 5-6 gentle motions maintain distinct layers.
Wipe knife clean between cuts for neatest edges on bars.
Chill bars for 30 minutes before cutting for even easier slicing.
Room temperature eggs mix more smoothly for better texture.
Sprinkle mini chocolate chips and chopped walnuts on top before baking for extra appeal.
Use parchment sling overhang for easy removal from pan.
Store in airtight container at room temperature for up to 4 days.
Refrigerate for up to 1 week or freeze individual bars for up to 3 months.
Bars taste even better the next day once flavors have melded.
- Prep Time: 20 minutes
- Cook Time: 40 minutes
- Category: Dessert
- Method: Baking
- Cuisine: American