Moist Banana Sheet Cake with Cream Cheese Frosting

Banana sheet cake is the answer when you have a bunch of overripe bananas on the counter and need a dessert that feeds a crowd without much work. The batter comes together in one bowl, and the pan goes straight into the oven.

You get a tender, moist crumb that holds its softness for days, which makes it ideal for making ahead. A thick layer of tangy cream cheese frosting balances the sweetness, and you can slice and serve it right from the pan.

Why This Banana Sheet Cake Works

The crumb is genuinely moist because it uses a good amount of spotty bananas and just enough buttermilk to keep things tender. It stays soft on the counter longer than most cakes, so leftovers never dry out.

The cream cheese frosting adds a bright tang that cuts through the sweetness. The batter itself needs only a bowl and a whisk, no mixer required, which makes cleanup easy.

Ingredients

• 3 overripe bananas (about 1 1/2 cups mashed): they should be heavily spotted, or even black, for the strongest banana flavor
• 1/2 cup unsalted butter, melted: plus a little extra to grease the pan
• 3/4 cup granulated sugar
• 1/4 cup packed light brown sugar
• 2 large eggs: at room temperature
• 1 tsp vanilla extract
• 1/2 cup buttermilk: well shaken
• 2 cups all-purpose flour
• 1 tsp baking soda
• 1/2 tsp salt
• Cream Cheese Frosting
• 8 oz cream cheese, softened: use full-fat block cream cheese
• 1/4 cup unsalted butter, softened
• 2 cups powdered sugar: sifted if it has lumps
• 1 tsp vanilla extract

Variations / Substitutions

• Nutty: fold 1/2 cup chopped walnuts or pecans into the batter before baking
• Chocolate: add 1/2 cup mini chocolate chips for little bursts of cocoa
• Sour cream: swap the buttermilk for the same amount of full-fat sour cream; the cake will be slightly richer
• Dairy-free: use a neutral oil instead of butter in the cake, your favorite plant-based cream cheese for the frosting, and soured oat milk for the buttermilk
• Extra banana: stir in 1/2 teaspoon banana extract to boost the flavor

Banana Dump Cake is another dessert you’d probably love if you enjoy this cake.

How to Make Banana Sheet Cake

Step 1: Mash the Bananas and Mix the Wet Ingredients

In a large bowl, mash the 3 overripe bananas with a fork until mostly smooth with a few small lumps. Add the 1/2 cup melted butter, 3/4 cup granulated sugar, 1/4 cup brown sugar, 2 eggs, 1 tsp vanilla, and 1/2 cup buttermilk, then whisk until the mixture is uniform and slightly thick, about 30 seconds.

You will still see small flecks of banana in the bowl, and that is exactly what you want. A smooth puree is fine, but those little pieces keep the cake extra moist.

Step 2: Add the Dry Ingredients

Sprinkle the 2 cups flour, 1 tsp baking soda, and 1/2 tsp salt right over the wet mixture. Stir with a spatula or wooden spoon just until no streaks of flour remain, about 20 gentle strokes.

The batter will look pale and a bit lumpy in spots from the banana, but stop mixing the moment the flour disappears. Overworking it now will make the cake dense.

Step 3: Bake the Cake

Heat your oven to 350°F (175°C). Grease a 9 x 13 inch metal or glass baking pan with butter, then scrape the batter into the pan and spread it evenly to the corners. Bake for 25 to 30 minutes, until the top is golden brown and a toothpick inserted in the center comes out clean with just a few moist crumbs.

The cake will pull away slightly from the edges when it is done. Set the pan on a wire rack and let it cool completely before you frost it, otherwise the frosting will melt.

Step 4: Frost and Slice the Cake

In a medium bowl, beat the 8 oz softened cream cheese and 1/4 cup softened butter with a hand mixer until smooth and creamy, about 1 minute. Beat in the 1 tsp vanilla, then gradually add the 2 cups powdered sugar on low speed until combined; once it is incorporated, increase speed and beat until light and fluffy, about 2 minutes total. Spread the frosting over the completely cooled cake with an offset spatula or the back of a spoon.

Slice the cake right in the pan and serve. The frosting will be thick and creamy, and the crumb underneath should be moist and amber-flecked.

Tips for the Best Banana Sheet Cake

• Use bananas that are deeply spotted or almost black. That is when they are sweetest and pack the most banana flavor.
• Sift the powdered sugar if it has any lumps so the frosting turns out perfectly smooth.
• If you want a taller cake, bake in a 9 inch square pan and increase the bake time by about 10 to 15 minutes, checking for doneness.
• The cake tastes even better the next day after the frosting and crumb have a chance to settle, so it is a great make-ahead dessert.

Bake times by pan size:

Storing Leftovers

Because the frosting contains cream cheese, keep the cake covered in the refrigerator for up to 4 days. You can serve it cold straight from the fridge, or let slices sit at room temperature for about 15 minutes to soften the frosting.

What to Serve with Banana Sheet Cake

A strong cup of black coffee cuts right through the sweetness of the frosting and makes the banana flavor pop. Vanilla bean ice cream turns it into a more substantial dessert with a cold, creamy contrast. Fresh strawberries or blueberries add a juicy burst of acidity that keeps each bite interesting.

Frequently Asked Questions

Can I use frozen bananas?

Yes. Thaw them completely in a bowl and drain away any liquid that separates before mashing.

What if I do not have buttermilk?

Stir 1 1/2 teaspoons of lemon juice or plain white vinegar into 1/2 cup of milk. Let it sit for 5 minutes, then use it as you would the buttermilk.

Can I make this gluten-free?

You can. Swap in a 1 to 1 gluten-free all-purpose flour blend. The cake will be slightly more dense, but still tender and moist.

How long does the cake keep?

Frosted cake stays fresh in the fridge for up to 4 days. Unfrosted cake, wrapped well, can be frozen for up to 3 months.

Why did my cake sink in the middle?

Opening the oven door too early or overmixing the batter can cause sinking. Stir just until the flour disappears and resist checking until the 25-minute mark.

Banana Sheet Cake Recipe

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 25 minutes mins

Total Time 40 minutes mins

Servings: 12 servings

Calories: 385

Ingredients Method Notes

Ingredients

  

• 3 overripe bananas (about 1 1/2 cups mashed)
• 1/2 cup unsalted butter, melted
• 3/4 cup granulated sugar
• 1/4 cup packed light brown sugar
• 2 large eggs
• 1 tsp vanilla extract
• 1/2 cup buttermilk
• 2 cups all-purpose flour
• 1 tsp baking soda
• 1/2 tsp salt
• 8 oz cream cheese, softened
• 1/4 cup unsalted butter, softened
• 2 cups powdered sugar
• 1 tsp vanilla extract

Method

 

1. In a large bowl, mash the bananas with a fork, then whisk in the melted butter, sugars, eggs, vanilla, and buttermilk until combined.
2. Add the flour, baking soda, and salt. Stir just until no dry flour remains.
3. Pour into a greased 9 x 13 inch pan and bake at 350°F for 25 to 30 minutes, until a toothpick comes out clean. Cool completely.
4. Beat the cream cheese, butter, and vanilla until smooth, then beat in the powdered sugar until fluffy. Spread over the cooled cake, slice, and serve.

Notes

Use bananas that are heavily spotted for the deepest flavor. The cake can be baked a day ahead; store it unfrosted at room temperature, then frost before serving. If your bananas are small, use 4 to reach 1 1/2 cups mashed.