An overhead view of a slice of layered banana cake with frosting and caramel dripping down the side

Banana Cake with Browned Butter Rum Frosting

  • Author: Julianne Dell
  • Prep Time: 50 minutes
  • Cook Time: 22 minutes
  • Total Time: 1 hour 12 minutes
  • Yield: 10 slices


This Banana Cake features a homemade banana cake covered in a sweet browned butter frosting with a touch of spiced rum, crunchy walnuts and salted caramel drizzle. Serve for brunch or dessert, this is a perfect cake for any occasion.


For the cake:

  • ½ cup (113g) butter, softened
  • 1 ⅓ cups (254g) granulated sugar
  • 1 ½ (5g) teaspoons baking powder
  • ½ teaspoon baking soda
  • ¼ teaspoon salt
  • 1 large egg
  • 1 cup (229g estimated) mashed ripe bananas (about 3 medium bananas)
  • ½ cup (118ml) light sour cream
  • 1 teaspoon (5ml) pure vanilla extract
  • 2 cups (280g) all-purpose flour
  • ¾ cup (87g) chopped walnuts  or pecans (optional)

For the frosting:

  • 10 tablespoons (143g) unsalted butter, browned
  • 34 cups (390-520g) powdered sugar
  • 1 teaspoon (5g) cinnamon
  • 12 tablespoons spiced rum (30ml) (optional- flavored as desired)
  • 34 tablespoons (59ml) milk
  • 2 teaspoons pure vanilla (10ml) extract
  • Salted caramel sauce (optional)
  • Walnuts or Pecans for garnish (optional)


For the Cake:

  1. Preheat the oven to 350°F. Grease two 8-inch baking pans and line with parchment paper or a silicone mat; set aside.
  2. In a large mixing bowl beat butter with an electric mixer on medium speed for about 30 seconds.
  3. Next add the sugar, baking powder, baking soda, and salt. Beat until all ingredients are combined, scraping sides of bowl as needed.
  4. Beat in the egg, mashed bananas, sour cream, and vanilla until mix until combined.
  5. Next, add the flour and walnuts, beating as much as you can using the mixer, but being careful not to overmix. Then use a wooden spoon or spatula and, stir in any remaining flour and the walnuts.
  6. Pour the batter into the prepared baking pans, spreading evenly. Bake in a 350°F for 20-25 minutes. Test the cake for doneness by inserting a toothpick into the center of the cake. If the toothpick comes out clean, your cake is done. Cool completely.

For the Frosting:

  1. To brown the butter, use a small saucepan, and cut the butter into pieces. Melt the butter over medium heat and allow it to boil and bubble. Once it starts boiling, stir it frequently and it will slowly start to turn an amber color and releases a nutty aroma. Remove the butter from the heat and place in the freezer for 20-25 minutes and then stir until smooth.
  2. Slowly add the powdered sugar 1 cup at a time, alternating in some of the liquid ingredients (Rum, milk and vanilla). The frosting will be thick at times, but as you slowly add the liquid, it will become smoother. Beat the frosting each time you add the powdered sugar until the frosting is completely smooth, whipped and fluffy.
  3. Spread 1/3 of the frosting on top of the first layer, and drizzle some caramel and chopped nuts if desired. Then spread the remaining frosting over the cooled cake. Garnish with caramel and walnuts. Store in an airtight container.


  • The original cake recipe is from Better Homes and Gardens.
  • This can also be made in a 9-inch pan and reduce the bake time 3-5 minutes.
  • For more tips about brown butter, see my how-to post.
  • If you’d like to prepare the browned butter ahead of time (up to 3 days), you can place the butter in the refrigerator and leave it until it reaches a solid state. Then, you’ll simply melt the butter in the microwave for 30-60 seconds and stir it until it’s smooth. It won’t be completely melted, but just thick enough that you can get it nice and smooth.
  • Substitutes for Rum: The rum in the frosting is optional. To omit, sub with additional milk. You should need 2-4 tablespoons of liquid to achieve the right consistency for the frosting. Spiced rum is best.
  • Substitutes for sour cream: You can use plain or Greek yogurt.
  • Toast the Nuts: For added flavor, lightly toast the nuts for 5-10 minutes prior to adding them to the cake.
Nutrition Information:
1 slice
100 g
  • Category: Cake
  • Method: Baked
  • Cuisine: American