Banana Cake with Peanut Butter Frosting

5 from 1 vote

Banana Cake with Peanut Butter Frosting

This single layer banana cake with peanut butter frosting is super moist and so easy to make! Perfect for weekday baking & overripe bananas!

Prep Time20

Cook Time35

Total Time55

Course: Dessert

Cuisine: American

Diet: Vegetarian

Servings: squares

Calories: 512kcal

Author: Ella Gilbert

Equipment

1 8x8 baking pan

Ingredients

Banana Cake

½ cup unsalted butter
1 cup bananas mashed
½ cup light brown sugar
¼ cup white sugar
2 teaspoons vanilla extract
2 large eggs room temperature
¼ cup buttermilk room temperature
1 teaspoon baking soda
½ teaspoon baking powder
½ teaspoon ground cinnamon
½ teaspoon kosher salt
1 ¾ cup all purpose flour

Peanut Butter Frosting

⅓ cup granulated sugar
1 ½ teaspoons vanilla extract
¼ teaspoon kosher salt
½ cup heavy cream cold
¾ cup cream cheese cold
½ cup smooth peanut butter

Metric - US Customary

Instructions

Banana Cake

Preheat the oven to 350°Fahrenheit/175°Celsius. Grease and line an 8x8 baking pan with parchment paper and set aside. Make sure the parchment is overhanging so you can easily lift the cake out.
Melt the butter in a large microwave safe bowl. Whisk in the mashed banana.
½ cup unsalted butter, 1 cup bananas
Add the sugar and light brown sugar and whisk into the banana mixture for 1 minute.
¼ cup white sugar, ½ cup light brown sugar
Add in the two eggs, buttermilk and vanilla extract, whisking until almost smooth - it will be a little bit lumpy because of the banana which is fine!
2 large eggs, ¼ cup buttermilk, 2 teaspoons vanilla extract
Pour in the dry ingredients - the flour, baking soda, baking powder, salt and ground cinnamon. Use a rubber spatula to fold everything together until there are no more streaks of flour.
1 teaspoon baking soda, ½ teaspoon baking powder, ½ teaspoon kosher salt, 1 ¾ cup all purpose flour, ½ teaspoon ground cinnamon
Pour the cake batter into the prepared pan. Bake for 30-35 minutes. A toothpick inserted should come out with little to no crumbs. Let it cool in the pan for 20 minutes before gently lifting out and letting it cool completely on a wire cooling rack.

Peanut Butter Frosting

In a stand mixer with the whisk attachment, or a large bowl with a handheld mixer, whisk the heavy cream, salt, sugar and vanilla on medium-low for 2 minutes. The sugar needs to have completely dissolved.
⅓ cup granulated sugar, ¼ teaspoon kosher salt, ½ cup heavy cream, 1 ½ teaspoons vanilla extract
Increase the speed to high and whisk for 2 minutes, until it looks very thick like Greek yogurt.
Add the cream cheese and the peanut butter. Turn the speed to high, and whip for 3 minutes until smooth.
¾ cup cream cheese, ½ cup smooth peanut butter
Spread this peanut butter frosting on top of the banana cake.

Notes

My recipes have been developed and tested in metric grams. I highly recommend using a weighing scale and measuring out your ingredients the metric way.

Salt: If you don’t have kosher salt, halve the amount of salt called for in the recipe. 1 teaspoon kosher salt = ½ teaspoon fine salt. Please note I am using Diamond Crystal Kosher Salt and not Morton Salt, which is a coarse kosher salt. Coarse kosher salt is much too salty for this recipe.

Buttermilk: If you don’t have buttermilk, replace it with an equal amount of sour cream or full fat yoghurt. You can also make your own buttermilk, for every cup of buttermilk add 1 tablespoon of lemon juice to 1 cup of milk and let sit for 5 minutes.

Peanut Butter: I'm using commercial peanut butter, not natural peanut butter that has oil on top.

Storage: Keep tightly wrapped in the fridge or in an airtight container for up to 4 days. Let it come to room temperature before eating.

Nutrition