Go Back
–+ servings
Cut banana bars with penuche frosting are displayed in a metal pan. Two bars are tilted sideways, showing the frosted and banana layers, and a metal spatula is visible at the bottom of the image.
Print Recipe
5 from 7 votes

Banana Bars with Penuche Frosting

Soft, sweet Banana Bars are topped with an almost fudge-like penuche frosting made with caramelized brown sugar and are the perfect way to use up the overripe brown bananas sitting on your counter! This recipe is essentially a frosted banana sheet cake, but great for cutting into bars and serving a crowd!
Prep Time15 minutes
Cook Time20 minutes
Total Time35 minutes
Course: Dessert
Cuisine: American
Servings: 24 servings
Author: Amy Nash

Ingredients

Cake

  • 1 1/2 cups granulated sugar (300g)
  • 1/2 cup salted butter softened
  • 2 large eggs room temperature
  • 2 teaspoons pure vanilla extract
  • 1 1/2 cups mashed ripe bananas (about 3 medium bananas)
  • 1 cup sour cream room temperature
  • 2 cups all-purpose flour (281g)
  • 1 teaspoon baking soda
  • 1/2 teaspoon salt

Penuche Frosting

  • 1/2 cup salted butter
  • 1 cup brown sugar packed (200g)
  • 1/4 cup milk
  • 3 1/2 cups sifted powdered sugar

Instructions

Cake

  • Preheat the oven to 375°F. Spray a half sheet pan with baking spray or line with parchment paper.
  • In a large bowl, beat the sugar and butter together on medium-high speed for 2 to 3 minutes until creamy and light.
    1 1/2 cups granulated sugar, 1/2 cup salted butter
  • Add eggs and vanilla, mixing to combine. Add the mashed bananas and sour cream, mixing and scraping down the sides and bottom of the bowl as needed.
    2 large eggs, 2 teaspoons pure vanilla extract, 1 1/2 cups mashed ripe bananas, 1 cup sour cream
  • Add the flour, baking soda, and salt, mixing just until incorporated. Spread the batter into the prepared pan.
    2 cups all-purpose flour, 1 teaspoon baking soda, 1/2 teaspoon salt
  • Bake for 20 minutes until golden brown on top and a toothpick inserted in the center of the cake comes out clean.

Frosting

  • Melt the butter in a medium saucepan set over medium heat. Add the brown sugar and bring to a boil, stirring frequently.
    1/2 cup salted butter, 1 cup brown sugar
  • Add the milk, then remove from the heat.
    1/4 cup milk
  • Working quickly, whisk in the powdered sugar and pour over the still warm cake. Use a spatula to immediately spread the frosting around the top of the cake while it is still hot, then let it sit for 30 minutes to set up.
    3 1/2 cups sifted powdered sugar

Notes

  • Adding nuts: These bars would be delicious with the addition of chopped walnuts or pecans, either in the cake itself or sprinkled on top of the penuche frosting before it has a chance to set.
  • Cream cheese frosting: If you would rather have a more traditional cream cheese frosting, this one is our favorite.
  • Storage: These will keep for about 5 days on the counter stored in an airtight container. Or you can freeze the bars for up to 2 months. Let thaw on the counter for a couple of hours before serving. The bars are delicious warm, cold, or room temperature.

Nutrition

Calories: 292kcal | Carbohydrates: 50g | Protein: 2g | Fat: 10g | Saturated Fat: 6g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 3g | Trans Fat: 1g | Cholesterol: 39mg | Sodium: 179mg | Potassium: 82mg | Fiber: 1g | Sugar: 40g | Vitamin A: 326IU | Vitamin C: 1mg | Calcium: 28mg | Iron: 1mg

QR code

Scan this QR code with your phone's camera to view this recipe on your mobile device.

qr code