When life gives you extra ripe bananas, make Banana Sheet Cake. The easiest banana cake recipe because you start with a box mix, Banana Sheet Cake is perfect whether topped with a smooth and rich cream cheese frosting or a sprinkling of powdered sugar. Homemade doesn’t have to take all day.
Full disclosure: bananas as a fruit are not my thing. Before you swipe or hit the “X”, I’m not saying I don’t like bananas. I just like them IN things. Like in banana bread or this beyond simple Banana Sheet Cake.
True story: Grandma Nina used to
try and force beg me to eat bananas because “you need potassium, Lori.”
I was 10. What the heck kind of potassium did I need?
Now if Gram had put them in banana cake? Banana convert for life.
Banana Sheet Cake Ingredients
This Banana Sheet Cake requires:
- 1 box of yellow cake mix
- really ,really ripe bananas
- powdered sugar for sprinkling or in cream cheese frosting
It doesn’t get much simpler than that!
Baking with Bananas
using overripe bananas
When your bananas are pretty dark and spotty, that’s the time to bake with them. Or if you don’t have time to bake with them, you can freeze them for use in smoothies, pancakes, cakes, muffins or breads. And a potato masher does a beautiful job creating the perfect texture for baking.
How to Freeze bananas
- Peel the bananas and slice then in half.
- Load up a freezer bag, label it with the date and lay them flat in your freezer.
- Take out as needed for your recipes.
- A great way to thicken and sweeten a green smoothie!
Can I use frozen bananas to bake with?
Absolutely! Just defrost them for a bit or throw them in the microwave but drain off any extra water. The banana “juice” is fine to throw in.
3 very ripe bananas mashed = approximately 1 cup
Easy Banana cake from a mix
Don’t tell—but this banana sheet cake starts with a boxed cake mix.
It’s ok to take shortcuts, especially if they taste as good as from scratch and save you time. You might not believe this, but there are lots of professional bakers out there who regularly use boxed cake mixes. Super Moist is a fav of many professional chefs.
A few boxed cake tips from the pros:
- substitute milk for water
- substitute butter for oil
- watch your baking time. Set your oven at least 5 minutes sooner than the box suggests and use your nose and cake tester to tell you when it’s done.
Time to mix it up
- Start with pouring your boxed cake mix into a bowl and add the wet ingredients. Refer to the substitutions above.
- If you are out of milk and butter, the water will work just fine because the bananas add so much richness.
- Using a stand or hand mixer on medium, mix the cake according to the package but DON’T OVERMIX. Overmixing develops the gluten making for a super dense cake.
Add the mashed bananas stirring with a wooden spoon. Pour the cake into a prepared baking pan.
What icing goes best with Banana cake?
- Cream cheese.
- Plain powdered sugar.
- Browned butter caramel.
- Any of the above and more!
Tricks to smooth Homemade cream cheese frosting
There’s nothing worse looking at or eating a cake with lumpy cream cheese frosting. Here’s how to avoid lumps in your next batch of homemade frosting:
- sift or whisk your powdered sugar before using. Use a flour sifter for super airy results but if you don’t have one, you can use a whisk as well.
- set your creamed cheese and butter on the counter until softened. It shouldn’t feel cold anywhere. Cold ingredients are the enemies to smooth homemade frosting.
- whip on high speed
- cool your cake completely and use an icing spatula to frost your cakes for a smooth finish.
How to get really moist banana cake
Place the cake in the freezer for 45 minutes right after baking for the best banana cake. This trick came actually from another banana cake recipe and works beautifully.
For a few: Make this recipe into regular or mini cupcakes and only frost what you need. Freeze the rest of the cupcakes unfrosted. Thaw and frost before serving.
For a crowd: Pour into a large jelly roll pan (approx 15″ x 10″) for a thinner cake that feeds more.
Banana Sheet Cake with Cream Cheese Frosting
- 1 boxed yellow cake mix, I use Super Moist
- 1 cup milk, can use water if necessary
- 1/3 cup butter, softened, can use oil as well
- 1 teaspoon cinnamon
- 3 ripe bananas, mashed, approx 1 cup
Cream Cheese Frosting
- 8 ounces cream cheese, room temperature,softened
- 1/2 cup butter, room temperature, softened
- 2 teaspoons vanilla extract
- 2 Tablespoons milk, more if needed
- 3 cups powdered sugar, sifted
- Preheat oven to 350°
- Follow the package directions to prepare the cake mix adding the mix and eggs (as recommended by the box directions) but use butter instead of oil and milk instead of water to a mixing bowl. Use the measurements for all the ingredients delineated by the package.
- Mix either with a hand mixer, whisk or stand mixer on medium for 2 minutes until thoroughly combined. Don't overmix to avoid making too dense of a cake.
- Add mashed bananas in by hand with a wooden spoon. Again, don't overmix.
- Pour cake mix into a prepared 9×13" pan, spreading to even out.
- Bake for approximately 30 minutes until cake tester or toothpick inserted in the center comes out clean.
- Remove the cake from the oven and place the cake in the freezer for 45 minutes. Trust me – this will make the cake very moist. Remove from the freezer and finish cooling on a rack before frosting.
For Cream Cheese Frosting
- Read all the instructions below thoroughly before starting.
- In a medium bowl. whisk or sift the powdered sugar until fluffy and almost no lumps remain. Set aside
- Add butter and cream cheese to a different mixing bowl and cream them together with a hand or stand mixer until fluffy, about 2 minutes on medium high. Stop to scrape down the sides as needed.
- Alternate adding powdered sugar with milk to the cream cheese/butter mix, ending with the milk and stopping the mixer in-between additions, Mix on low and ramp up to medium high with each addition (this is to avoid a big mess…you're welcome).
- Add more milk or powdered sugar as needed to achieve the desired spreading consistency.
- Add vanilla and the pinch of salt at the end.
- Plop large spoonfuls of frosting equally across the cooled cake and spread an even layer of frosting using an flat icing spatula.
- Don’t skip the freezing step to cool the cake. This makes for a really moist cake.
- Make sure to have your frosting ingredients at room temp for smooth frosting.
- Double the frosting as needed for larger or layer cakes.