Sourdough Banana Muffins (Walnut Crumb Topping)

A delicious and unique twist on classic banana nut muffins. The use of sourdough starter adds a tangy depth of flavor, besides being a great way to use discard starter.

Moist and delicious with the best (BEST!) crumb topping. These are easy enough to make every Saturday morning, just like I do 😊.

plate of banana muffins.

Sourdough Banana Muffins

Moist and sweet, this recipe is a must-try for anyone looking to experiment with sourdough baking or anyone who loves a good banana nut muffin.
Prep Time 15 minutes
Cook Time 20 minutes
Total Time 35 minutes
Serving Size 15 muffins


  • 2 muffin tins


Muffin Batter

  • cup vegetable oil or melted butter
  • 1 cup white sugar
  • 1 egg
  • 3 very ripe bananas mashed
  • 1 cup discard sourdough starter stirred
  • 1 ½ cups all-purpose flour
  • ½ teaspoon salt
  • ¾ cup walnuts chopped
  • 1 teaspoon baking powder
  • 1 teaspoon baking soda

Brown Sugar Oatmeal Crumb Topping

  • ½ cup quick oats
  • ¼ cup all-purpose flour
  • ¼ teaspoon salt
  • ¼ cup brown sugar
  • 2 tablespoons chopped walnuts
  • 4 tablespoons unsalted butter melted


  • Prep. Preheat oven to 375. Prepare a muffin pan by lining with paper liners. You can either make 12 oversize muffins or 15 regular sized muffins.
  • Make the batter. Beat the oil, sugar, vanilla, and egg in a mixing bowl with an electric mixer on medium. Add the mashed banana and sourdough starter, mixing on low. In a separate medium mixing bowl, mix the flour, salt, baking soda, and baking powder. Add it to the wet ingredients and mix on low until just combined. Add in the walnuts, if using.
    3 stages of mixing batter.
  • Make the topping. Whisk together oats, flour, sugar, and salt. Stir in butter until clumps form.
    crumb topping in small white bowl.
  • Assemble. Pour batter into muffin tin, filling ¾ of the way full. Sprinkle 1-2 tablespoons of topping on each.
    batter with crumb topping before baking.
  • Bake. Bake for 20 minutes, or until a toothpick comes out just with moist crumbs. Carefully remove to a wire rack to cool. Serve warm or room temperature.
    12 muffins on cooling rack.


To freeze, allow to cool completely and flash freeze, uncovered until frozen. Then place in a freezer bag and freeze for 2-3 month.
Calories: 285kcal | Carbohydrates: 39g | Protein: 4g | Fat: 13g | Saturated Fat: 3g | Polyunsaturated Fat: 4g | Monounsaturated Fat: 2g | Trans Fat: 0.1g | Cholesterol: 19mg | Sodium: 224mg | Potassium: 151mg | Fiber: 2g | Sugar: 20g | Vitamin A: 126IU | Vitamin C: 2mg | Calcium: 33mg | Iron: 1mg
stack of sourdough banana muffins with crumb topping.

❤️ Why you’ll love this recipe

  • Moist and delicious. The muffin batter is made with mashed ripe bananas and discard starter, giving the muffins a moist, tender crumb with a satisfying crunch from the walnuts.
  • The crumb topping! The brown sugar oat topping is the perfect finishing touch to these muffins. It adds a sweet and crunchy texture to the muffins, elevating their flavor and making them look beautiful.
  • Versatile. These muffins are great for a quick breakfast on the go, an afternoon snack, or even as a dessert. They can also be frozen and reheated, making them a great make-ahead option for busy mornings or unexpected guests.

This is an overview of the ingredients. You’ll find the full measurements and instructions in the printable recipe at the bottom of the page.

ingredients on marble counter.

You’ll need the following for these delicious muffins:

  • vegetable oil or melted butter
  • granulated sugar
  • egg
  • very ripe bananas
  • discard sourdough starter
  •  all-purpose flour
  • salt
  • walnuts 
  • baking powder
  • baking soda
  • quick oats
  • brown sugar
  • butter


Step One: make the batter

3 stages of mixing batter.

Preheat your oven to 375°F (190°C) and line a muffin tin with paper liners.

In a large mixing bowl, beat together the vegetable oil (or melted butter), white sugar, vanilla, and egg using an electric mixer on medium speed.

Add the mashed bananas and sourdough starter to the mixing bowl, and mix on low speed until the ingredients are well combined.In a separate medium mixing bowl, whisk together the all-purpose flour, salt, baking powder, and baking soda.

Add the dry ingredients to the wet ingredients in the large mixing bowl, and mix on low speed until the batter is just combined. Fold in the chopped walnuts, if using.

Step Two: make the crumb toping

crumb topping in small white bowl.

In a small mixing bowl, whisk together the quick oats, all-purpose flour, salt, and brown sugar. Stir in the chopped walnuts.

Melt the unsalted butter in a separate bowl, then add it to the mixture and stir until clumps form.

Step three: assemble

batter with crumb topping before baking.

Pour the muffin batter into the prepared muffin tin, filling each cup about three-quarters of the way full.

Sprinkle about 1 tablespoon of the brown sugar oat topping over the top of each muffin.

Step Four: bake and cool

12 muffins on cooling rack.

Bake. Bake for 20 minutes, or until a toothpick comes out just with moist crumbs. Carefully remove to a wire rack to cool. Serve warm or room temperature.

🥫 Storage instructions

These muffins can be stored in an airtight container at room temperature for up to 3 days. They can also be stored in the refrigerator for up to 1 week or in the freezer for up to 3 months. If freezing, be sure to allow the muffins to cool completely before placing them in a freezer-safe container.

🔍 FAQs

Can I use whole wheat flour instead of all-purpose flour?

Yes, but keep in mind that the texture of the muffins may be slightly denser and the flavor may be slightly more nutty. You can also try using a mixture of whole wheat flour and all-purpose flour for a balance between flavor and texture.

Can I use a different type of nuts in this recipe?

Of course, you can use any type of nuts that you like or have on hand. Pecans, almonds, or hazelnuts would all be delicious substitutions for walnuts.

How can I make this recipe vegan?

Any vegan substitute for the egg and butter will work just fine. 😊

👩🏻‍🍳 Expert tips

  • Use ripe bananas: The riper the bananas, the sweeter and more flavorful your muffins will be. Make sure your bananas are very ripe and mash them thoroughly to ensure even distribution throughout the batter.
  • Don’t overmix the batter: Overmixing the batter can result in tough, dense muffins. Mix the ingredients until they are just combined, and avoid over-stirring.

📘 Related Recipes

finished muffin with missing bite.
Sourdough Banana Muffins (Walnut Crumb Topping)Sourdough Banana Muffins (Walnut Crumb Topping)
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Recipe Rating


  1. 5 stars
    These came out perfect. Made these with the melted butter. Used 1/2 cup sugar and 1/2 cup Monk fruit.

  2. 5 stars
    These are delicious! I made them with the melted butter instead of oil. They were done in a little under 20 minutes.
    Thank you!