Banana Bread With Peanut Butter Protein Swirl – Moist, Comforting, and Packed With Flavor

Banana bread is already cozy and comforting, but this version adds a bold peanut butter protein swirl that makes each slice feel a little more special. It’s moist, tender, and not overly sweet, with a nutty ribbon running through the crumb. The batter comes together with pantry staples, and the swirl takes just an extra minute.

Bake it on a Sunday, and you’ll have a satisfying breakfast or snack all week. It also freezes beautifully, so you can stash a few slices for later.

What Makes This Recipe So Good

• Moist and tender texture: Overripe bananas and a touch of yogurt or sour cream keep the loaf soft without being heavy.
• High-protein swirl: Peanut butter mixed with protein powder adds staying power and a delicious, nutty contrast.
• Balanced sweetness: Just enough sugar to highlight the banana flavor without making it cloying.
• Simple method: Two bowls, one pan, and minimal fuss. No mixer required.
• Meal-prep friendly: Slices hold up well for quick breakfasts, snacks, or post-workout bites.

Ingredients

• 3 large overripe bananas, mashed (about 1 1/3 cups)
• 2 large eggs, room temperature
• 1/3 cup neutral oil or melted butter
• 1/3 cup plain Greek yogurt or sour cream
• 1/2 cup light brown sugar, packed
• 1 teaspoon vanilla extract
• 1 3/4 cups all-purpose flour (or use half whole-wheat pastry flour)
• 1 teaspoon baking soda
• 1 teaspoon baking powder
• 1/2 teaspoon fine salt
• 1 teaspoon ground cinnamon (optional)
• 1/2 cup chocolate chips or chopped dark chocolate (optional)

For the Peanut Butter Protein Swirl

• 1/3 cup creamy natural peanut butter (stirred well)
• 2 to 3 tablespoons vanilla or unflavored whey or plant-based protein powder
• 2 tablespoons milk of choice (plus 1 more tablespoon if needed)
• 1 tablespoon maple syrup or honey (optional, for sweetness)
• Pinch of salt

How to Make It

1. Prep the pan and oven: Heat oven to 350°F (175°C).

   Line a 9×5-inch loaf pan with parchment, leaving overhang for easy lifting. Lightly grease the sides.

2. Mix the wet ingredients: In a large bowl, whisk mashed bananas, eggs, oil, yogurt, brown sugar, and vanilla until smooth and well combined.
3. Whisk the dry ingredients: In a separate bowl, combine flour, baking soda, baking powder, salt, and cinnamon. Stir to blend.
4. Combine batter: Add dry ingredients to wet and stir with a spatula until just combined.

   If using chocolate chips, fold them in gently. Do not overmix.

5. Make the swirl: In a small bowl, stir peanut butter, protein powder, milk, maple syrup, and a pinch of salt. The mixture should be thick but pourable, like warm peanut butter.

   Add a splash more milk if needed.

6. Layer and swirl: Pour half the banana batter into the pan. Spoon half the peanut butter mixture in dollops over the batter. Add the remaining banana batter, then the rest of the peanut butter mixture.

   Use a butter knife to gently swirl, making a few figure-eights. Don’t overdo it.

7. Bake: Bake 50 to 60 minutes, until the top is golden and a toothpick inserted in the center comes out with just a few moist crumbs (avoid a peanut butter pocket when testing).
8. Cool: Let the loaf cool in the pan 10 to 15 minutes. Lift out using the parchment and cool fully on a rack before slicing.

   This helps set the crumb and swirl.

How to Store

• Room temperature: Wrap tightly or store in an airtight container for up to 3 days. Add a paper towel to absorb excess moisture.
• Refrigerator: Keeps well for 5 to 6 days. Bring to room temp or warm slightly before serving.
• Freezer: Slice, wrap each piece, and freeze up to 2 months.

  Thaw at room temp or microwave 20 to 30 seconds.

Why This is Good for You

• Protein boost: The peanut butter and protein powder add satiety, making a slice more satisfying than standard banana bread.
• Healthy fats and fiber: Peanut butter offers heart-healthy fats, while bananas provide fiber and potassium.
• Moderate sugar: Using ripe bananas lets you keep added sugar in check without losing flavor.
• Customizable nutrition: You can swap flour types, adjust protein, or reduce sugar to fit your needs.

Pitfalls to Watch Out For

• Overmixing the batter: This can make the loaf tough. Stir just until the flour disappears.
• Too thick or too thin swirl: If it’s paste-like, it won’t swirl; if it’s runny, it may sink. Aim for a thick, ribbon-like consistency.
• Underbaking: Peanut butter pockets can throw off doneness tests.

  Check multiple spots and look for a springy top.

• Using cold ingredients: Cold eggs or yogurt can stiffen the batter. Room-temperature ingredients mix more evenly.
• Not letting it cool: Slicing too soon can smear the swirl and collapse the crumb.

Variations You Can Try

• Almond twist: Swap peanut butter for almond butter and add a dash of almond extract.
• Chocolate lovers: Use chocolate protein powder and add cocoa to the swirl for a fudgy ribbon.
• Nut-free: Use sunflower seed butter and a nut-free protein powder.
• Whole-grain: Replace half the all-purpose flour with whole-wheat pastry flour for extra fiber.
• Crunch factor: Top with chopped peanuts or a sprinkle of turbinado sugar for a crisp crust.
• Spice it up: Add nutmeg or cardamom to the batter for warmth and depth.

FAQ

Can I use frozen bananas?

Yes. Thaw them completely, drain excess liquid, and mash.

The flavor is great, and the texture works well in quick breads.

What type of protein powder works best?

Whey blends in smoothly and tastes neutral. Plant-based powders work too but may thicken the swirl more, so add an extra splash of milk to reach a ribbon-like consistency.

Can I make this dairy-free?

Use oil instead of butter, a dairy-free yogurt, and plant-based milk. Choose a dairy-free protein powder as well.

How do I prevent the loaf from sinking in the middle?

Measure leaveners accurately, avoid overmixing, and bake until fully set.

Let it cool in the pan briefly, then on a rack so steam can escape.

What if I don’t have brown sugar?

Use granulated sugar and add 1 teaspoon of molasses if you have it. Otherwise, plain sugar will work, but the flavor will be a bit lighter.

Can I bake this as muffins?

Yes. Divide batter and swirl into a greased or lined 12-cup muffin pan.

Bake at 350°F (175°C) for 18 to 22 minutes, or until a toothpick comes out with a few moist crumbs.

Is the swirl too sweet with maple syrup?

The maple syrup is optional. If your protein powder is sweetened, skip it. Taste the swirl and adjust as needed.

Do I need both baking soda and baking powder?

Yes.

The bananas and yogurt provide acidity for the baking soda, while baking powder ensures a reliable rise and tender crumb.

Wrapping Up

This Banana Bread with Peanut Butter Protein Swirl brings comfort and nutrition together in one simple loaf. It’s easy enough for a weekday bake and special enough to share. Keep a few slices on hand for busy mornings, or freeze a stash for later.

If you try a variation, note your favorite—this is a recipe that invites repeats. Enjoy it warm, with a little extra peanut butter on top if you like.