These Sourdough Zucchini Muffins are an easy sourdough discard recipe made with fresh zucchini, warm cinnamon, and a sweet streusel topping. They bake up soft and tender with a bakery-style texture, making them the perfect breakfast or snack.

Several sourdough zucchini muffins with cinnamon streusel topping on a wooden counter.

Gardening and sourdough baking are two of my favorite hobbies. So I love when I get to combine the two. Every summer, my garden gives me more zucchini than I know what to do with (not that I’m complaining!), and these sourdough zucchini muffins are one of my favorite ways to use it up.

I recently gave this recipe a little update by adding a cinnamon streusel topping, increasing the baking powder for a better rise, and adjusting the baking method to create taller, bakery-style muffins. Now, they look just like something you’d pick up from a bakery, but they’re actually so simple to make at home.

With a buttery flavor, warm cinnamon spice, and a soft, tender crumb, these muffins are the perfect way to use up extra zucchini and sourdough discard. Enjoy them warm with a little butter, dolloped with jam, or just grab one straight from the container. You really can't go wrong!

And if you have an abundance of zucchini this summer, be sure to check out my classic sourdough zucchini bread or chocolate zucchini bread too!

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Ingredients & Substitutions

Here are some notes on key ingredients. For a full list of ingredients, check out the recipe card below.

Sourdough Discard- Adds moisture, flavor, and is a great way to use up extra discard. Active sourdough starter works just as well.
Zucchini- Finely grate the zucchini using a box grater so it blends seamlessly into the batter. If your zucchini is especially watery, gently blot away excess moisture with paper towels, but don't squeeze it completely dry.
All-Purpose Flour- Provides structure and keeps the muffins light and tender. You can substitute up to ⅓ of the flour with whole wheat flour for a heartier muffin.
Brown & Granulated Sugar- Brown sugar adds moisture and a subtle caramel flavor, while granulated sugar helps create a lighter crumb. If needed, you can use all brown sugar or all granulated sugar, though the texture and flavor will vary slightly.
Unsweetened Applesauce- Keeps the muffins moist and tender. I recommend using one individual 3.9-ounce (111-gram) cup for easy measuring.
Butter- Adds rich flavor and tenderness. You can substitute an equal amount of a neutral-flavored oil, such as avocado or vegetable oil.
Streusel Topping- Cold butter is key to creating a crumbly topping. Keep the streusel chilled while you prepare the batter so it stays crisp during baking.
Kosher Salt- I use Diamond Crystal Kosher Salt (about 2.8 grams per teaspoon). If using Morton Kosher Salt or table salt, measure by weight or use half the amount.

The ingredients to make sourdough zucchini muffins. Each ingredient is labeled with text. They include sourdough discard, butter, baking powder, baking soda, vanilla, sugar, cinnamon, eggs, brown sugar, salt, applesauce, all-purpose flour, and zucchini.

Tips for Success

Measure your flour accurately. Weigh the flour with a kitchen scale for the most accurate results. If using measuring cups, spoon the flour into the cup and level it off. Too much flour can make the muffins dry and dense.
Use finely grated zucchini. Finely grate the zucchini with the small holes of a box grater so it melts into the batter. If your zucchini is especially watery, gently blot it with paper towels, but don't squeeze it completely dry.
Don't overmix the batter. Stir the dry ingredients into the wet ingredients just until no streaks of flour remain. Overmixing develops the gluten and can make the muffins dense instead of light and tender.
Keep the streusel cold. Refrigerate the streusel while you mix the batter so the butter stays cold. This helps create crisp, crumbly clusters on top of the muffins.
Customize with mix-ins. Fold in up to 1 cup of chocolate chips, chopped walnuts, pecans, or dried cranberries for an easy variation.

How to Make Sourdough Zucchini Muffins

These bakery-style sourdough zucchini muffins are simple to make in just a few easy steps. Scroll to the recipe card below for the full recipe and ingredient amounts.

Step 1: Make cinnamon streusel. Stir together the flour, brown sugar, cinnamon, and salt. Cut in the cold butter until crumbly.

Two hands pinching butter into flour, sugar, and cinnamon in a bowl.

Step 2: Combine dry ingredients. Whisk together the flour, cinnamon, baking powder, baking soda, and salt.

The dry ingredients being whisked in a glass bowl.

Step 3: Mix wet ingredients. In a separate bowl, whisk together the melted butter, brown sugar, granulated sugar, eggs, applesauce, sourdough discard, and vanilla until smooth.

The wet ingredients, including sourdough discard, being whisked in a bowl.

Step 4: Make the batter. Add the dry ingredients to the wet ingredients and stir just until combined. Fold in the grated zucchini.

Sourdough discard muffin batter in a bowl.

Sourdough zucchini muffin batter in a bowl.

Step 5: Fill and top. Divide the batter evenly among the muffin cups. Sprinkle generously with the streusel.

A standard 12-cup muffin pan with paper liners filled with sourdough discard zucchini muffin batter.

Cinnamon streusel being pressed on top of the sourdough zucchini muffins before baking.

Step 6: Bake and cool. Bake at 425°F for 5 minutes, then, without opening the oven door, reduce the temperature to 375°F and bake for 15–18 minutes. Let the muffins cool in the pan for 5 minutes before transferring them to a wire rack to cool completely.

Baked cinnamon streusel sourdough zucchini muffins in a muffin pan.

How to Store

Store completely cooled sourdough zucchini muffins in an airtight container at room temperature for 2-3 days.

For longer storage, freeze muffins in a freezer-safe container for up to 3 months. Thaw at room temperature and warm before serving.

Several sourdough zucchini muffins with cinnamon streusel topping on a wooden counter. One of the muffins is removed from the liner and split in half to show the crumb.

A cover of a recipe ebook with the title "Everyday Sourdough: 27 Sweet & Savory Sourdough Discard Recipes." There is an image of sourdough discard cinnamon rolls on the front. At the bottom, it reads "By Ashley Petrie of Everyday Homemade."

Grab a copy today!

Are you tired of watching your sourdough discard go to waste?

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No more guilt about wasting your discard - with Everyday Sourdough, you have endless options to quickly make something amazing anytime.

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