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A slice of cake being taken from a chocolate banana cake

Chocolate Banana Cake

Course Dessert
A moist and sweet chocolate cake made with bananas and cake mix. Don't forget the frosting!
Prep Time 20 mins
Cook Time 35 mins
Total Time 55 mins
Servings 12 slices


For the Cake

  • 1 15 oz. box chocolate cake mix
  • 3 eggs
  • 1 cup buttermilk or homemade buttermilk substitute
  • 1 tbs vegetable oil
  • 1 tsp vanilla extract
  • 1 tsp cinnamon
  • 1 1/2 cups mashed bananas about 3 ripe bananas, fully mashed

For the Frosting

  • 1/2 cup salted butter 1 stick
  • 1 tsp salt
  • 1 tsp lemon juice
  • 1/2 cup mashed ripe banana
  • 3 cups powdered sugar
  • 1/3 cup cocoa powder
  • 1 tsp espresso powder optional
  • 2-3 tbsp heavy cream or whole milk


Cake Instructions

  • Preheat the oven to 350 F. Grease and flour two 9” round baking pans. (I like to use this flour coating baking spray)
  • Whisk or beat together cake mix, buttermilk, eggs, vegetable oil, vanilla extract, and cinnamon.Fold in mashed bananas until just combined.
  • Pour cake batter into the prepared baking pans. Bake for 35 to 40 minutes, until a toothpick tests clean.Take cakes out of the oven and set aside to cool.
    Once the cakes have finished cooling, make the frosting.

Frosting Instructions

  • In a large bowl or using a stand mixer, mix together the butter, salt, lemon juice, vanilla extract, and bananas until combined.
  • Turn the mixer on low and add in 3 cups powdered sugar, cocoa powder, espresso powder, and 2 Tablespoons heavy cream. Mix until ingredients are completely incorporated together. You may need to add in 1 additional Tablespoon cream if the frosting is still dry and the powdered sugar isn’t incorporating.
  • Turn mixer on high and beat frosting for 5 minutes, scraping down the sides halfway through. The frosting should be light and fluffy.

To Assemble the Cake

  • Place one of the cooled cakes on top of a flat plate or serving platter.
    Spread ⅓ of the chocolate frosting on the cake. Lay the other cake on top of the frosted cake.
    Use the remaining frosting to frost the tops and sides of both cakes. Let chill in the refrigerator or freezer for 15 minutes to set (optional). Slice and enjoy!


Calories: 262kcal | Carbohydrates: 41g | Protein: 3g | Fat: 11g | Saturated Fat: 7g | Trans Fat: 1g | Cholesterol: 64mg | Sodium: 301mg | Potassium: 213mg | Fiber: 2g | Sugar: 35g | Vitamin A: 355IU | Vitamin C: 3mg | Calcium: 41mg | Iron: 1mg