How to Make Soft Banana Bread Brownies
Use ripe bananas with plenty of brown spots so they mash easily into the batter. Beat the sugar, sour cream, softened butter, and eggs until creamy, then stir in the mashed bananas and vanilla. Add the dry ingredients and stir just until the flour disappears.
Spread the batter into a greased 9-by-13-inch baking dish and bake at 375°F (190°C) for about 25 minutes. The bars are ready when the top is golden and a toothpick inserted in the center comes out clean.
How to Brown the Butter for the Frosting
Use a light-colored saucepan so you can see the milk solids change color. As the butter melts and foams, stir and watch for golden-brown flecks on the bottom. As soon as the butter smells nutty, take it off the heat and pour it into a heatproof mixing bowl to stop the browning.
Whisk in the powdered sugar and vanilla, then add the milk a little at a time until the frosting spreads easily. Smooth it over the still-warm bars, then let them cool completely so the frosting can set before slicing.
Banana Bread Brownies with Brown Butter Frosting Recipe Card
Soft banana squares with golden edges and a nutty brown butter frosting.
- Prep time — 15 minutes
- Bake time — About 25 minutes
- Cooling — Cool completely before slicing
- Yield — 12 squares
Banana Brownies
- 1½ cups granulated sugar
- 1 cup sour cream
- ½ cup butter, softened
- 2 large eggs
- 3 ripe bananas, mashed
- 2 teaspoons vanilla extract
- 2 cups all-purpose flour
- 1 teaspoon baking soda
- ¾ teaspoon salt
- ½ cup chopped walnuts, optional
Brown Butter Frosting
- ½ cup butter
- 3 cups powdered sugar
- 3 tablespoons milk, added gradually
- 1½ teaspoons vanilla extract
Instructions
- Preheat the oven to 375°F (190°C). Grease a 9-by-13-inch baking dish.
- In a large bowl, beat the granulated sugar, sour cream, softened butter, and eggs until creamy. Stir in the mashed bananas and vanilla.
- In a separate bowl, whisk together the flour, baking soda, and salt. Stir into the banana mixture just until no dry streaks remain. Fold in the walnuts, if using.
- Spread the batter evenly in the baking dish. Bake for about 25 minutes, until the top is golden and a toothpick inserted in the center comes out clean.
- While the bars cool slightly, melt the frosting butter in a light-colored saucepan over medium heat. Stir as it foams. When the milk solids turn golden brown and smell nutty, remove the pan from the heat and pour the butter into a heatproof bowl.
- Whisk in the powdered sugar and vanilla, adding the milk gradually until the frosting is smooth and spreadable.
- Spread the frosting over the still-warm bars. Let them cool completely in the dish, then cut into 12 squares.