Quick Recipe Version (TL;DR)
Quick Ingredients
- 1 cup (2 sticks/226 g) unsalted butter, softened
- 1 1/2 cups (300 g) granulated sugar
- 1/2 cup (100 g) light brown sugar, packed
- 3 large eggs, room temperature
- 1 cup (240 g) mashed very ripe bananas (about 3 medium)
- 1 cup (240 g) sour cream
- 2 teaspoons vanilla extract
- 2 cups (260 g) all-purpose flour
- 1 teaspoon baking soda
- 1/2 teaspoon baking powder
- 1/2 teaspoon fine salt
- 1/2 teaspoon ground cinnamon (optional)
- 8 oz (226 g) cream cheese, softened
- 1/2 cup (1 stick/113 g) unsalted butter, softened (for frosting)
- 3 cups (360 g) powdered sugar
- 2 teaspoons vanilla extract (for frosting)
- 1–3 tablespoons milk or cream, as needed
- Chopped walnuts or pecans, for garnish (optional)
Do This
- 1. Preheat oven to 350°F (175°C). Grease and line a 9×13-inch pan with parchment, leaving overhang.
- 2. Cream 1 cup butter with granulated and brown sugars until fluffy. Beat in eggs one at a time.
- 3. Mix in mashed bananas, sour cream, and 2 tsp vanilla until smooth.
- 4. Whisk flour, baking soda, baking powder, salt, and cinnamon. Gently mix into wet ingredients just until combined.
- 5. Spread batter in pan. Bake 22–27 minutes, until golden and a toothpick comes out clean. Cool completely.
- 6. Beat cream cheese and 1/2 cup butter until smooth. Add powdered sugar, vanilla, and enough milk/cream to make a thick, spreadable frosting.
- 7. Spread frosting over cooled bars. Garnish with nuts if desired, chill briefly to set, then slice into 24 bars.
Why You’ll Love This Recipe
- Ultra-moist, banana-scented bars that taste like a cross between banana bread and snack cake.
- Luxurious, tangy cream cheese frosting that balances the sweetness perfectly.
- Easy to bake in one 9×13-inch pan, ideal for potlucks, church suppers, and family gatherings.
- Stays moist for days, so you can make it ahead without worrying it will dry out.
Grocery List
- Produce: Very ripe bananas (about 3 medium)
- Dairy: Unsalted butter, sour cream, cream cheese, milk or heavy cream, eggs
- Pantry: All-purpose flour, granulated sugar, light brown sugar, powdered sugar, vanilla extract, baking soda, baking powder, salt, ground cinnamon (optional), chopped walnuts or pecans (optional)
Full Ingredients
For the Banana Bars
- 1 cup (2 sticks/226 g) unsalted butter, softened to room temperature
- 1 1/2 cups (300 g) granulated sugar
- 1/2 cup (100 g) light brown sugar, packed
- 3 large eggs, at room temperature
- 1 cup (240 g) mashed very ripe bananas (about 3 medium bananas)
- 1 cup (240 g) sour cream (full-fat preferred)
- 2 teaspoons vanilla extract
- 2 cups (260 g) all-purpose flour, spooned and leveled
- 1 teaspoon baking soda
- 1/2 teaspoon baking powder
- 1/2 teaspoon fine sea salt or table salt
- 1/2 teaspoon ground cinnamon (optional but lovely)
- 1/2 cup (60 g) chopped walnuts or pecans (optional, folded into batter)
For the Tangy Cream Cheese Frosting
- 8 oz (226 g) cream cheese, softened to room temperature
- 1/2 cup (1 stick/113 g) unsalted butter, softened
- 3 cups (360 g) powdered sugar, sifted if lumpy
- 2 teaspoons vanilla extract
- 1–2 teaspoons fresh lemon juice (optional, for extra tang)
- Pinch of fine salt, to taste
- 1–3 tablespoons milk or heavy cream, as needed for consistency
For Garnish (Optional)
- 2–3 tablespoons finely chopped walnuts or pecans, for sprinkling
- Light dusting of ground cinnamon or nutmeg, for a cozy finish
Step-by-Step Instructions
Step 1: Prep the Pan and Heat the Oven
Preheat your oven to 350°F (175°C) with a rack in the center position. Lightly grease a 9×13-inch metal baking pan with butter or nonstick spray. For easy removal and clean slicing, line the bottom and two long sides with parchment paper, leaving a slight overhang to lift the bars out later. Lightly grease the parchment as well.
Set your butter, cream cheese, and eggs out ahead of time so they can come to room temperature. This helps the batter whip up light and the frosting turn out silky smooth. Peel and mash the bananas in a bowl with a fork until mostly smooth with just a few small lumps.
Step 2: Make the Banana Bar Batter
In a large mixing bowl (or the bowl of a stand mixer), combine 1 cup softened butter, 1 1/2 cups granulated sugar, and 1/2 cup packed light brown sugar. Beat on medium-high speed for 2–3 minutes, until the mixture looks light and fluffy and slightly lightened in color. Scrape down the bowl as needed.
Add the eggs one at a time, beating well after each addition until fully incorporated. Mix in the mashed bananas, 1 cup sour cream, and 2 teaspoons vanilla extract. Beat on low until the mixture is smooth and well combined. It may look slightly curdled at first; keep mixing gently and it will come together.
Step 3: Combine the Dry Ingredients and Fold Together
In a separate medium bowl, whisk together the flour, baking soda, baking powder, salt, and cinnamon (if using) until everything is evenly distributed. This prevents pockets of leavening or spice from ending up in your bars.
Add the dry ingredients to the wet mixture in two additions, mixing on low speed or folding gently with a spatula just until no streaks of dry flour remain. If you are using chopped nuts, fold them in now. Take care not to overmix; a few small lumps are fine. Overmixing can make the bars tough instead of tender.
Step 4: Bake Until Golden and Set
Scrape the batter into your prepared 9×13-inch pan and smooth the top with an offset spatula or the back of a spoon so it is level all the way to the corners. Bake at 350°F (175°C) for 22–27 minutes.
The bars are done when the top is lightly golden, the edges are just pulling away from the sides of the pan, and a toothpick inserted in the center comes out clean or with a few moist crumbs (no wet batter). If your oven runs hot or cool, check a couple of minutes early and adjust the time as needed.
Step 5: Cool the Bars Completely
Set the pan on a wire rack and allow the banana bars to cool completely, 30–45 minutes. Frosting a warm cake will cause the cream cheese frosting to melt and slide, so do not rush this step.
Once the pan is cool to the touch, you can slide it into the refrigerator for 15–20 minutes to speed things up slightly, but avoid chilling so long that the bars get very cold and firm; slightly cool room temperature is ideal for frosting.
Step 6: Beat the Tangy Cream Cheese Frosting
In a clean mixing bowl, beat the softened cream cheese and 1/2 cup softened butter together on medium-high speed until completely smooth, lump-free, and creamy, about 2 minutes. Scrape down the bowl.
Gradually add the powdered sugar, about 1/2 cup at a time, mixing on low at first so it does not puff out of the bowl. Once incorporated, increase the speed to medium and beat until thick and fluffy. Add 2 teaspoons vanilla extract, a pinch of salt, and lemon juice if using. Beat to combine.
Adjust the consistency by adding 1–3 tablespoons milk or heavy cream, a little at a time, until the frosting is thick but easily spreadable. It should hold soft peaks and glide smoothly over the cooled bars without tearing the surface.
Step 7: Frost, Garnish, and Slice
Once the banana bars are completely cool, spread the cream cheese frosting evenly over the top using an offset spatula. Swirl or smooth the surface as you like. For a classic Amish-style look, keep the frosting in soft, rustic waves rather than perfectly sharp edges.
If desired, sprinkle finely chopped walnuts or pecans evenly over the frosting, and add a light dusting of cinnamon or nutmeg for a warm, cozy finish. For the cleanest cuts, chill the frosted bars in the refrigerator for 20–30 minutes to let the frosting firm slightly.
Use the parchment overhang to lift the slab out of the pan and onto a cutting board. With a long, sharp knife, cut into 24 bars (4 by 6 grid). Wipe the knife clean between cuts for neat edges. Serve slightly cool or at room temperature.
Pro Tips
- Use very ripe bananas: The browner and spottier the bananas, the more sweetness and banana flavor they bring. Green or just-yellow bananas will taste bland.
- Measure flour carefully: For tender, moist bars, spoon flour into your measuring cup and level it off instead of scooping directly from the bag, which packs it down and adds too much.
- Do not overbake: Pull the bars from the oven as soon as a toothpick comes out clean or with moist crumbs. Overbaking is the fastest way to lose that ultra-moist texture.
- Room temperature ingredients: Softened butter, cream cheese, and eggs blend more easily, creating a finer crumb and ultra-smooth frosting.
- Chill before slicing: A short chill sets the frosting, so your knife glides cleanly and the layers stay tidy, especially if transporting to a gathering.
Variations
- Nutty Banana Bars: Stir 1/2–3/4 cup toasted walnuts or pecans into the batter and sprinkle extra on top of the frosting for a pleasant crunch and classic old-fashioned flavor.
- Spiced Banana Bars: Increase the cinnamon to 1 teaspoon and add a pinch of nutmeg and cloves for a cozy, spice-cake twist.
- Lighter Frosting: For a slightly less sweet topping, use 2 1/2 cups powdered sugar and add an extra teaspoon of lemon juice to boost the tang. The frosting will be softer but still spreadable.
Storage & Make-Ahead
Because of the cream cheese frosting, store the banana bars covered in the refrigerator. They keep well for 4–5 days and actually taste even better on day two as the flavors meld. For serving, let the bars sit at room temperature for 20–30 minutes so the texture softens and the flavors bloom.
To make ahead, you can bake the banana bars a day in advance, cool completely, wrap tightly in plastic wrap or foil, and refrigerate. Prepare and spread the frosting the day you plan to serve, or frost up to a day ahead and keep covered in the fridge. For longer storage, freeze the unfrosted bars well-wrapped for up to 2 months. Thaw overnight in the refrigerator, then frost and garnish as desired.
Nutrition (per serving)
Approximate values per bar (1 of 24), including frosting: about 290 calories; 15 g fat; 9 g saturated fat; 38 g carbohydrates; 1 g fiber; 28 g sugar; 3–4 g protein; 210 mg sodium. These numbers are estimates and will vary based on specific ingredients and portion sizes.
