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Banana Bread Brownies

Banana Bread Brownies combine ripe mashed bananas with a fudgy, moist batter that bakes until golden and set, then finish with a brown butter glaze. You get a tender banana crumb in every square, with a sweet powdered-sugar topping that melts into the top.
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Prep Time 35 minutes
Total Time 35 minutes
Servings: 12 servings
Course: Dessert
Cuisine: American
Calories: 340
Ingredients Equipment Method Notes

Ingredients
  

1 1/2 cups sugar
  • 1.5 cup sugar
1/2 cup sour cream
  • 0.5 cup sour cream
1/2 cup butter, softened
  • 0.5 cup butter
2 large eggs
  • 2 eggs
1 1/2 cups mashed ripe banana
  • 1.5 cup mashed ripe banana
1 teaspoon vanilla extract
  • 1 tsp vanilla extract
2 cups all-purpose flour
  • 2 cup all-purpose flour
1 teaspoon baking soda
  • 1 tsp baking soda
1/2 teaspoon salt
  • 0.5 tsp salt
1/2 cup chopped walnuts, optional
  • 0.5 cup chopped walnuts optional
1 cup powdered sugar
  • 1 cup powdered sugar
3 tablespoons milk
  • 3 tbsp milk

Equipment

  • 1 sheet pan

Method
 

Prep and bake
  1. Preheat the oven to 375°F and grease a 9x13-inch baking pan, leaving a thin film so the brownies release cleanly.
  2. Beat the sugar, sour cream, softened butter, and eggs together until well combined and glossy, with no visible streaks of butter.
  3. Add the mashed banana and vanilla extract, mixing until combined so the batter looks thick and evenly speckled.
  4. Stir in the all-purpose flour, baking soda, and salt until just combined, then fold in chopped walnuts if using to keep the crumb tender.
  5. Pour the batter into the prepared pan and bake for 20 to 30 minutes, until a toothpick comes out clean and the edges look set with light golden color.
Brown butter glaze and finish
  1. Melt butter until browned for the glaze, watching for amber-brown flecks and a nutty aroma.
  2. Whisk in powdered sugar and milk until smooth, thick, and pourable.
  3. Pour the glaze over the cooled brownies so it settles on top without running off.

Notes

For the smoothest glaze, cool the brownies until warm-not-hot so the brown butter doesn’t split. Store covered at room temperature up to 2 days or refrigerate up to 5 days; freeze in a sealed container up to 2 months. For a dairy-light option, use dairy-free butter and sour cream-style plant alternative (the texture remains similar, though flavor will be slightly different).