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Banana Bread Brownies

These banana bread brownies merge the moist, banana-infused texture of classic banana bread with the decadent indulgence of fudgy brownies topped with a luscious brown butter frosting. The recipe is forgiving and perfect for using up overripe bananas, while walnuts add a satisfying crunch. It’s a unique twist that will delight anyone looking for a comforting yet elevated dessert.
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Prep Time 15 minutes
Cook Time 25 minutes
Total Time 40 minutes
Servings: 12 squares
Course: Dessert
Cuisine: American
Ingredients Equipment Method Notes

Ingredients
  

For the Banana Bread Brownie Base
  • 1 1/2 cups sugar
  • 1 cup sour cream
  • 1/2 cup butter softened
  • 2 eggs
  • 3-4 bananas mashed
  • 2 teaspoons vanilla extract
  • 2 cups all-purpose flour
  • 1 teaspoon baking soda
  • 3/4 teaspoon salt
  • 1/2 cup walnuts chopped
For the Brown Butter Frosting
  • 1/2 cup butter
  • 4 cups powdered sugar
  • 1 1/2 teaspoons vanilla extract
  • 3 tablespoons milk

Equipment

  • 15×10-inch jelly roll pan
  • Large bowl
  • Large saucepan
  • Spatula

Method
 

  1. Preheat your oven to 375°F and prepare a 15×10-inch jelly roll pan by greasing it and lightly dusting with flour.
  2. In a large bowl, beat together 1½ cups sugar, 1 cup sour cream, ½ cup softened butter, and 2 eggs until the mixture is creamy.
  3. Stir in the 3-4 mashed bananas and 2 teaspoons vanilla extract, ensuring the banana flavor is well distributed.
  4. Add the dry ingredients—2 cups all-purpose flour, 1 teaspoon baking soda, and ¾ teaspoon salt—and blend for about a minute until just incorporated.
  5. Gently fold in ½ cup chopped walnuts, which will add a nice crunch to the tender base.
  6. Spread the batter evenly into the prepared pan and bake for 20-25 minutes or until the top turns a beautiful golden brown.
  7. While the brownies are baking, prepare the brown butter frosting. In a large saucepan over medium heat, melt ½ cup butter and continue heating until it starts to foam and turns a delicate brown color, being careful not to burn it.
  8. Remove the browned butter from the heat and immediately whisk in 4 cups powdered sugar, 1½ teaspoons vanilla extract, and 3 tablespoons milk until the frosting is smooth and spreadable.
  9. Once the brownies have cooled slightly, use a spatula to evenly spread the brown butter frosting over the top. Cut into squares and serve.

Notes

This recipe is very forgiving and open to creative substitutions. You can replace walnuts with chocolate chips or dried cranberries for a different twist, and if you run out of sour cream, Greek yogurt works beautifully. The brown butter frosting, with its nutty, caramel-like flavor, elevates these brownies to a whole new level. Enjoy them warm with a scoop of vanilla ice cream for an extra indulgent treat.