Banana Bread Brownies

These banana bread brownies are like the best parts of banana bread and frosted sheet cake smashed into one dreamy bar. They’re super moist and soft from ripe bananas and sour cream, with a bit of crunch from chopped pecans. On top, a rich brown-butter frosting adds a nutty, caramel flavor that makes them taste like something from a bakery. They’re perfect for using up overripe bananas, and they bake in a 9×13 pan, so they’re great for parties, potlucks, or after-school treats. Serve them chilled or at room temperature and watch them disappear fast.

Ingredients

• Brownies:
  • 2 eggs
  • 1 ½ cups white sugar
  • 1 cup regular sour cream
  • 1 stick unsalted butter (room temp)
  • 3 large ripe bananas, mashed
  • 2 teaspoons pure vanilla extract
  • 2 cups all-purpose flour
  • 1 teaspoon baking soda
  • ¾ teaspoon kosher salt
  • 2 cups pecans, chopped
• Frosting:
  • ½ cup unsalted butter
  • 3 cups powdered sugar
  • 1 ½ teaspoons pure vanilla extract
  • 3 tablespoons whole milk

Directions

1. Preheat the oven to 375°F and prep a 9×13-inch baking pan with nonstick baking spray. Line the pan with parchment paper, then spray the parchment as well.
2. In a large mixing bowl, add the sugar, sour cream, softened butter, and eggs. Use an electric mixer to beat until the mixture is smooth and well blended.
3. Add the mashed bananas and vanilla extract to the bowl and mix again until combined.
4. In a separate bowl, whisk together the flour, baking soda, and salt.
5. Add the dry ingredients to the wet ingredients and stir just until everything is mixed together.
6. Stir in the chopped pecans until evenly distributed through the batter.
7. Pour the batter into the prepared baking pan and spread it into an even layer.
8. Bake at 375°F for 20–30 minutes, or until a toothpick inserted into the center comes out clean.
9. Remove the pan from the oven and set aside to cool completely before frosting.
10. Make the brown butter for the frosting: Slice the stick of chilled butter and add it to a heavy skillet over medium heat.
11. Cook, whisking often, until the butter melts, foams, and small brown specks appear on the bottom of the skillet and it smells nutty. Immediately pour the browned butter into a bowl and let it cool slightly.
12. Add 1 cup of powdered sugar to the brown butter and stir well. Continue adding the remaining powdered sugar, 1 cup at a time, stirring after each addition until smooth.
13. Add the milk and vanilla extract, then use an electric mixer to beat until the frosting is smooth and spreadable.
14. Spread the frosting over the cooled banana brownies, covering the corners and center evenly.
15. Let the frosting set, then cut into bars and serve.

Prep Time: 25 minutes | Cooking Time: 25 minutes | Total Time: 50 minutes
Kcal: 380 kcal | Servings: 16

Tips

For the best texture, use very ripe bananas (lots of brown spots) and be careful not to overmix the batter once you add the flour—this keeps the brownies soft and tender instead of dense.

Let the brown butter cool just a bit before adding the powdered sugar so the frosting thickens properly; store cooled bars in an airtight container at room temperature for a day or two, or in the fridge for up to 5 days.

FAQ

Can I leave out the pecans?
Yes, you can omit them or swap in another nut like walnuts, or even chocolate chips, if you prefer.

Do these taste more like banana bread or brownies?
They’re more like dense, moist banana bars with frosting—think banana bread texture but in brownie form.

Can I use Greek yogurt instead of sour cream?
You can replace the sour cream with plain Greek yogurt for a similar tang and moisture.

Do I have to brown the butter for the frosting?
Browning the butter adds a nutty, caramel flavor that really elevates the bars, but you can use simply melted butter if you’re short on time.

Can I freeze banana bread brownies?
Yes, freeze them (frosted or unfrosted) well wrapped in a container; thaw in the fridge or at room temperature before serving.