This is a side view of a plate with a slice of banana oat flour cake. The cake has peanut butter frosting. The plate sits on a white counter with a bite background.
Banana oat flour cake is super moist and decadent. It’s naturally gluten free and topped with a fluffy peanut butter whipped cream frosting!

Oat flour cake is loaded with banana flavor and has the most fluffy peanut butter frosting on top! This cake is a mix between banana bread meets moist cake.

It’s truly a no-fuss cake. You mix it up in one bowl, bake it up and whip up the peanut butter frosting once it’s cool. Easy peasy.

I made this into a two layer 6 inch cake, but you cake definitely pour the batter into a square or rectangular pan for a sheet pan cake. It may make the slice cutting that much easier, but it’s up to you!

Ingredients and substitutions for this banana oat flour cake:

Bananas. You know those ripe, spotty bananas sitting on your counter? They’re soft, slightly brown? Grab ’em!

Eggs. Just two. If you don’t have any eggs or don’t want to use eggs, you can use your favorite egg replacer.

Agave Nectar. Honey or maple syrup also works if you want to sub it in.

Vanilla Extract. Just a splash for that vanilla, cakey vibes.

Oat Flour. I love using oat flour lately. If you don’t have any oat flour on hand, pulse some old fashioned oats in your blender or food processor until it forms a powder-y flour. Viola! You have oat flour.

Baking Powder & Salt. This is where the baking magic happens.

Ingredients for fluffy whipped peanut butter frosting

Heavy cream. I haven’t tested this with coconut cream or a dairy free alternative, so if you do any experimenting, let me know how it goes!

Peanut Butter. I use natural peanut butter, but other peanut butters or nut/seed butters would probably work here too.

Agave Nectar. For some sweetness! You can sub honey or maple syrup if you prefer!

Make this oat flour cake your own!

I wanted to make a classic banana cake so didn’t fold in any add-ins. But, add 1/2 cup chocolate chips or walnuts (or both!) to add some texture to this cake!

How to make this banana oat flour cake:

Mix up the cake batter. Mash the bananas in a large bowl. Add the eggs, agave nectar, and vanilla. Whisk until combined. Add the oat flour, baking powder, and salt. Whisk again until combined. 

Transfer to a pan and bake. Line a two 6 inch circle pans with parchment paper and divide the batter between the pans. Bake for 20 minutes until a toothpick comes out clean. 

Cool completely. Allow the bread to cool at room temperature.

Make the frosting. Place the heavy cream in a large bowl. Use an electric mixer and whip on high for 3 minutes until it starts to have soft peaks. Add the peanut butter and agave. Mix again and continue to whip for a couple more minutes until the frosting stiffens and turns into a whipped cream. 

Assemble the cake. Place one layer of cake on a plate of cake stand. Add some of the frosting and smooth it out across the top of the cake. Add the second layer on top and add more frosting to the top of the cake. Smooth it around the top and sides of the cake. 

Chill and enjoy! Chill the cake for about an hour for the frosting to firm up a bit. Slicing into it immediately will be a bit difficult as the top layer can slide off the bottom layer.

More banana recipes to try

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This is a side view of a plate with a slice of banana oat flour cake. The cake has peanut butter frosting. The plate sits on a white counter with a bite background.

Moist Banana Oat Flour Cake

  • Author: Lindsay Grimes Freedman
  • Prep Time: 15 min
  • Cook Time: 20 min
  • Total Time: 35 min
  • Yield: 1 cake (8 slices) 1x
  • Category: dessert
  • Method: oven
  • Cuisine: cake
  • Diet: Gluten Free
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Description

Banana oat flour cake is super moist and decadent. It’s naturally gluten free and topped with a fluffy peanut butter whipped cream frosting!


Scale

Ingredients

Banana Cake:

  • 3 ripe bananas (1 1/4 cup mashed banana)
  • 2 eggs
  • 1/4 cup agave nectar (honey or maple syrup)
  • 1 teaspoon vanilla extract
  • 1 cup oat flour
  • 2 teaspoons baking powder
  • 1/2 teaspoon salt

Peanut Butter Frosting:

  • 1 pint heavy whipping cream
  • 1/4 cup natural peanut butter
  • 1/4 cup agave nectar (honey or maple syrup)

Instructions

  1. Preheat oven to 350F.
  2. Mash the bananas in a large bowl.
  3. Add the eggs, agave nectar, and vanilla.
  4. Whisk until combined.
  5. Add the oat flour, baking powder, and salt.
  6. Whisk again until combined. 
  7. Line a two 6 inch circle pans with parchment paper and divide the batter between the pans.
  8. Bake for 20 minutes until a toothpick comes out clean. 
  9. Allow the bread to cool at room temperature.
  10. Place the heavy cream in a large bowl.
  11. Use an electric mixer and whip on high for 3 minutes until it starts to have soft peaks.
  12. Add the peanut butter and agave.
  13. Mix again and continue to whip for a couple more minutes until the frosting stiffens and turns into a whipped cream. 
  14. Place one layer of cake on a plate of cake stand.
  15. Add some of the frosting and smooth it out across the top of the cake.
  16. Add the second layer on top and add more frosting to the top of the cake. Smooth it around the top and sides of the cake. 
  17. Chill the cake for about an hour for the frosting to firm up a bit. Slicing into it immediately will be a bit difficult as the top layer can slide off the bottom layer.


Nutrition

  • Serving Size: 1 slice
  • Calories: 401
  • Sugar: 19.6g
  • Sodium: 188mg
  • Fat: 28.1g
  • Saturated Fat: 15.1g
  • Unsaturated Fat: 0g
  • Trans Fat: 0g
  • Carbohydrates: 33.2g
  • Fiber: 2.3g
  • Protein: 6.9g
  • Cholesterol: 123mg

Keywords: oat flour cake, gluten free banana cake, healthy banana cake,