Gluten-Free 30-Minute Fluffy Banana Oat Flour Cake
This tender, naturally sweetened cake combines mashed ripe bananas with oat flour for a wholesome texture that's both fluffy and moist. The rich peanut butter whipped cream frosting adds indulgent flavor while chopped walnuts provide a satisfying crunch on top. Perfect for breakfast, dessert, or afternoon snacking, this quick-baking cake comes together in just 30 minutes and makes great use of overripe bananas. The oat flour keeps it hearty while the agave nectar provides gentle sweetness that lets the banana flavor shine through.
Ingredients
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 an 8x8 or 9x9 square pan with parchment paper and transfer the batter to the pan
- 8
Bake for 15 minutes until a toothpick comes out clean
- 9
Allow the cake 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
Smooth the whipped frosting on top of the cake and top with chopped walnuts
- 15
Cut into 12 square slices
- 16
Enjoy immediately or chill the cake for about an hour for the frosting to firm up a bit
Tips
Use very ripe bananas with brown spots for maximum sweetness and easier mashing
Don't overmix the batter once flour is added to keep the cake tender
Chill the cake for an hour after frosting to help the whipped cream set properly
Good to Know
Cover and refrigerate up to 3 days. Best served within 24 hours for optimal frosting texture.
Cake can be baked 1 day ahead and frosted before serving. Wrap unfrosted cake tightly.
Serve chilled or at room temperature. Cut with a sharp knife wiped clean between slices.
Common Mistakes
Don't overbake or the cake will be dry - check with toothpick at 15 minutes
Don't overwhip the cream or it will become grainy and separate
Substitutions
Dairy-Free Swaps
Gluten-Free Swaps
General Alternatives
FAQ
Can I make this without the frosting?
Yes, the cake is delicious on its own or dusted with powdered sugar. It's naturally sweet from the bananas and agave.
What if I don't have oat flour?
Make your own by grinding old-fashioned oats in a blender or food processor until fine. One cup oats makes about 3/4 cup oat flour.
How long will this cake keep?
Store covered in the refrigerator for up to 3 days. The frosting may soften at room temperature after a few hours.