Old-Fashioned Banana Sheet Cake is a moist and flavorful treat that’s been a beloved favorite for generations.

This banana sheet cake recipe delivers a perfectly moist and rich dessert with ripe bananas, a luscious sour cream batter, and a unique fluffy frosting that’s a true crowd-pleaser.

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I absolutely adore good ol’ church suppers.

You know the ones – a large gathering where a wonderful mishmash of dishes, from cheesy casseroles to creamy coleslaw and everything in between, makes its way to the potluck table.

And of course, the desserts are always a showstopper.

It’s like a food lover’s paradise, where you can sample a little bit of everything without feeling guilty.

I was originally introduced to a layer cake version of this easy banana cake by a precious lady in our church back when I was in my early 20s.

Miss Betty was a super sweet older woman who rode motorcycles and baked killer cakes. One Sunday, she brought in the best banana cake I’d ever had.

It had all the banana flavor of Sour Cream Banana Bread but was adorned with the creamiest and fluffiest frosting you could imagine.

One bite and I was in cake heaven!

Thankfully, Miss Betty shared her coveted recipe with me, and over the years, I’ve taken that cherished recipe and made it my own.

I’ve converted it into a moist banana sheet cake, which is easier to make, assemble, and transport.

The finished product looks a little different but the taste is just like Miss Betty’s cake, with that old-fashioned banana sheet cake appeal.

More Banana Recipes You’ll Love:

• Cranberry Banana Bread
• Banana Pear Bread
• Pistachio Banana Bread
• Bisquick Banana Muffins
• Banana Pear Cake
• Banana Pudding Puppy Chow

Secrets to Moist Banana Sheet Cake

One of the things I love about old-fashioned cake recipes is the ingenious ways home cooks ensured they had a moist and delicious cake.

For instance, Tomato Soup Cake uses canned condenses tomato soup, whereas Homemade Granny Cake uses crushed pineapple and juice.

This old-fashioned banana sheet cake has a few secrets of its own that make it moist and irresistible. It’s all about the ingredients and a few handy techniques.

Here’s the lowdown:

Ripe Bananas: The key to a moist banana cake is using perfectly ripe bananas. They should be really spotty and fairly brown.

As bananas ripen, their starches turn into sugars, making them sweeter and adding moisture to your cake.

Mash them up well to ensure even distribution in the batter.

I squeeze overripe bananas into a freezer bag and keep them in the freezer until I have enough to make this cake.

Sour Cream: This is your secret weapon!

What does sour cream do in baking? It adds a significant amount of moisture to the cake.

It also helps keep the cake tender and soft.

Butter: Using unsalted butter in the cake batter contributes to the richness and moistness of the cake.

Creaming it with the sugar properly is crucial. Creaming means beating the butter and sugar together until it’s light and fluffy, which incorporates air into the mixture and helps trap moisture.

Proper Mixing: Be gentle when mixing your dry ingredients (flour and baking soda) into the wet ingredients.

Overmixing can lead to a tougher, drier cake. Mix only until everything is combined.

Frosting Technique: This frosting is sometimes known as “boiled milk frosting” or “ermine icing.”

It plays a big role in keeping the cake moist as well.

In your frosting recipe, the use of flour and milk is a unique approach. This creates a thick, almost pudding-like base for your frosting, which makes it rich, fluffy, and creamy.

Just be sure to let it cool completely before incorporating it into the butter and sugar mixture. This will help maintain a fluffy texture without any graininess.

Storage: After baking, store the cake properly.

A moist cake can quickly dry out if not stored correctly. Keep it covered with plastic wrap or in an airtight container.

If you want to take things up a notch, consider adding a layer of plastic wrap or parchment paper between the cake and the container lid to seal in that moisture.

So, there you have it!

Ripe bananas, sour cream, and the right technique when mixing and frosting are the secrets to keeping your banana sheet cake wonderfully moist.

More Old-Fashioned Cake Recipes That Will Make You a Potluck Hero:

• Buttermilk Texas Sheet Cake
• Butterscotch Cake
• Preacher Cake with Cream Cheese Frosting
• Peanut Butter Sheet Cake with Dark Chocolate Frosting
• Pistachio Dream Whip Cake
• Old-Fashioned Strawberry Shortcake

How to Make Old-Fashioned Banana Cake

It’s really easy to make this simple yet delicious dessert.

Ingredients You’ll Need:

For the Cake:

• Unsalted butter
• Granulated Sugar
• Eggs
• Sour Cream
• Vanilla Extract
• Ripe Bananas
• All-purpose Flour
• Baking Soda

For the Boiled Milk Frosting:

• All-purpose Flour
• Milk
• Unsalted Butter
• Granulated Sugar
• Vanilla Extract

How to Make this Moist Banana Cake Recipe:

(Full printable recipe card is available below)

Cream the butter and sugar. First, in a large bowl or the bowl of your stand mixer, you’ll beat together butter and sugar on medium-high speed until light and fluffy.

Add eggs and mix on low-medium speed until combined.

Complete the wet batter. Next, you’ll add sour cream and vanilla extract and mix until incorporated.

Add mashed bananas and mix until combined.

Add the dry ingredients. Next, you’ll add flour and baking soda, mixing on low speed just until incorporated.

Bake the sheet cake. Then, you’ll spread batter into prepared pan.

Bake until a toothpick inserted in the center of the cake comes out clean, about 25-30 minutes. Allow cake to cool completely.

Prepare the frosting. Next, While the cake is cooling, begin preparing the frosting.

In a small saucepan, whisk together flour and milk over medium heat.

Whisk constantly until the mixture is thickened like pudding or paste. Set aside to cool completely to room temperature.

Finish the frosting. Once flour mixture is cool, add butter and sugar to the bowl of a stand mixer fitted with the paddle attachment (or in a medium mixing bowl with an electric hand mixer).

Beat together until light and fluffy. Add the cooled flour/milk mixture and vanilla extract to the butter mixture.

Beat on high speed until it reaches the consistency of a fluffy frosting that’s similar to whipped cream texture (this takes me about 7-8 minutes).

Frost the cake. Last, you’ll spread the frosting over the cooled cake, then slice and serve!

Notes and Adaptations:

• Feel free to add 1/2 teaspoon of ground cinnamon to the batter when you’re adding the flour, if you want a hint of spice.
• If you don’t have sour cream on hand, you can use plain Greek yogurt (preferably whole milk yogurt or low-fat yogurt, rather than fat free).
• This frosting amount provides enough for a thin layer of frosting over the entire 10×15″ cake. If you’d like a thicker layer, you can double the frosting recipe.
• You can also use the pourable brown sugar frosting from this buttermilk sheet cake if you’d like a slightly different flavor profile!
• I have not made this recipe in a 9×13″ pan, but it will likely take a bit longer to bake in the smaller pan. I recommend checking it around 35 minutes and every few minutes thereafter to check for doneness.

Be sure to save this recipe to your desserts board on Pinterest!