The most delicious peanut butter banana cake frosted with peanut butter buttercream! This cake is simple, sweet, and is the perfect way to use up those ripe bananas in the most delicious way possible.

I have a huge list of essential cakes on my website, and I feel like this simple, but tasty, cake should be included right along with those ones!

This truly is the best peanut butter banana cake. The texture is incredibly moist and flavorful and I know you’re just going to love it! So let’s dive right in:

How to make the best peanut butter banana cake layers

Peanut Butter Banana Cake is soft, tender, has just enough banana flavor from those gorgeous bananas and lots of peanut butter! With my fool-proof recipe, you’ll love how it turn out perfect each and every time you make it. It’s nice to know you have a banana peanut butter cake recipe in your back pocket that will never let you down, eh? It starts with a box mix and then you doctor it up so that it tastes even better than scratch! If you know, then you know ;). If you haven’t tried this method yet, I challenge you to give it a go – it will change your whole baking world/game.

Ingredients for Peanut Butter Banana Cake

All you’ll need are a few simple ingredients:

  • Mashed up ripe bananas (about 3 small ones or 2 medium ones)
  • 1/4 cup peanut butter
  • Egg Whites – room temperature
  • Buttermilk – room temperature
  • Sour Cream – room temperature
  • Vegetable Oil
  • Vanilla
  • White Cake Mix (I prefer the taste and texture of Duncan Hines)

The directions in better detail are below with the recipe, but it’s super simple! Just preheat the oven, hand-stir the ingredients, sift in the cake mix, then bake!

Can I make this into cupcakes or a sheet cake?

Yes! All my recipes can be changed to different mediums for whatever you need them for. My recipe/photos here today are for my 2 8″ rounds, but you can make this recipe into whatever you want without having to change the ingredients or baking temperature. All that changes is the baking time. For cupcakes, split the batter into 24 cupcakes and bake for 12-15 min. For a sheet cake, spread the batter into a 9×13 pan and bake for 32-35 minutes. For three 6″ rounds, bake for 30-32 minutes.

How to make easy peanut butter buttercream

I’ve used this buttercream recipe on so many cakes. Each and every time, it’s absolutely a hit that everyone loves! It’s so soft and creamy, and compliments so many different flavors. This time, pairing it with peanut butter, was a win all around. The recipe is super easy to make – starting with my vanilla buttercream and adding in a bit of my favorite secret ingredient: Skippy creamy peanut butter! Yep, the brand matters here for taste and texture, so make sure to grab a jar of it and let’s get started.

Ingredients for the best peanut butter buttercream

There’s truly nothing out of the ordinary when it comes to the ingredients needed for my buttercream, but when it all comes together, the taste and texture are going to become your new favorite thing! It’s PERFECT and so easy to spread onto your cake or pipe into your bakes. Here’s what you’ll need:

  • Unsalted butter
  • salt
  • vanilla
  • heavy cream
  • Skippy creamy peanut butter
  • powdered sugar

The full detailed directions are below with the recipe, but the overall game-plan is to whip it all up in your stand mixer with a paddle attachment. If you have a hand mixer, that will work just fine, too.

Tips for serving

The bananas are a fun garnish on top, but we all know what bananas like to do when they’re out of their peels! If you’d like to serve your peanut butter banana cake with fresh banana slices like I have here, just make sure to slice them right before serving so that they stay nice and white! Otherwise, you can use dried bananas, too.

Video of making a peanut butter banana cake

Here’s a quick video of the process:

That’s it! I can’t wait for you to try this gorgeous and super tasty cake! I’d love to see it if you do – make sure to tag me @bakingwithblondie #bakingwithblondie so I can join in on all the fun.

Happy Baking!

Mandy xo

Get the Recipe: The Best Peanut Butter Banana Cake with Peanut Butter Buttercream

Tender Peanut Butter Banana Cake layers with soft and creamy peanut butter buttercream.
Servings: 12 slices
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Ingredients
 

Peanut Butter Banana Buttercream

  • 2-3 Ripe Bananas (3 small or 2 medium)
  • 1/4 cup Skippy Creamy Peanut Butter
  • 3/4 cup Buttermilk, room temperature
  • 2/3 cup Sour Cream, room temperature
  • 4 large egg whites, room temperature
  • 1/3 cup vegetable oil
  • 1 Tablespoon vanilla
  • 1 box white cake mix

Peanut Butter Buttercream

  • 1 1/2 cup unsalted butter, left out at room temperature for 10 minutes
  • 1 pinch salt
  • 1 Tablespoon vanilla
  • 1/2 cup Skippy creamy peanut butter
  • 1/2 cup heavy cream
  • 7-8 cups powdered sugar

Garnish

  • melted peanut butter for drizzling
  • sliced banana slices

Instructions
 

For the Peanut Butter Banana Cake Layers

  • Preheat the oven to 325 degrees, convection bake, and prep two cake rounds with baking spray, parchment rounds, or shortening + flour to prevent non-sticking. Set aside.
  • In a large bowl, hand-whisk together all the ingredients and then sift in the cake mix. Gently fold in the cake mix (don't overmix!) and then split the cake batter between the prepared cake pans. Bake for 32-25 minutes until the center is baked through. Don't overbake. Let cool completely, wrap in plastic wrap, then place into the freezer flat for easier stacking later.

For the Peanut Butter Buttercream

  • In a stand mixer fitted with the paddle attachment, whip up the butter until it's light and fluffy. Add in the salt, vanilla, peanut butter, and heavy cream and whip up again. Scrape down the sides, then slowly add in the powdered sugar on low speed until the powdered sugar has been fully incorporated. If too thick, add in a tablespoon or two more of heavy cream if needed. Flip the mixer on the highest speed and whip up for 2 minutes until the buttercream is light and fluffy. Beat down with a wooden spoon to remove any air bubbles.

Assemby

  • Add on a small bit of buttercream on the cake table or cardboard cake round. Place down the first cake layer. Spread on an even layer of buttercream, then add on the second cake layer. Press down firmly, then crumb coat the cake. Place into the freezer for 5 minutes to set the crumb coat, then add on the final layer of buttercream. I used a scallop cake scraper for the decorative sides on this one. Spread on some of the melted peanut butter if using, then hand place on the sliced bananas right before serving. Enjoy!
Author: Mandy Merriman – Baking with Blondie