Ingredients:
- 1½ cups white sugar
- 1 cup sour cream
- ½ cup butter, softened
- 2 eggs
- 1¾ cups mashed ripe bananas
- 2 teaspoons vanilla extract
- 2 cups all-purpose flour
- 1 teaspoon baking soda
- ¾ teaspoon salt
- ½ cup chopped walnuts (optional)
Frosting:
- ½ cup butter
- 4 cups confectioners’ sugar
- 3 tablespoons milk
- 1½ teaspoons vanilla extract
Instructions:
Preheat oven to 350 degrees F (175 degrees C). Grease and flour a 15×10-inch jelly roll pan.
Beat white sugar, sour cream, ½ cup softened butter, and eggs in a bowl with an electric mixer until creamy. Beat in bananas and 2 teaspoons vanilla extract. Add flour, baking soda, and salt; mix for 1 minute. Stir walnuts into batter until evenly incorporated. Spread batter in prepared pan.
Bake in the preheated oven until golden, about 27 minutes. Cool.
Melt ½ cup butter in a large saucepan over medium heat until bubbling and golden brown, 3 to 5 minutes. Remove from heat.
Whisk confectioners’ sugar, milk, and vanilla extract into melted butter until a smooth frosting consistency is reached. Spread frosting over cooled banana bars.