Double Chocolate Sourdough Zucchini Muffins

Last Updated on July 5, 2025 by Jamie Saechao

These double chocolate sourdough zucchini muffins are loaded with mini chocolate chips, cocoa powder, and zucchini!  Tender, moist, and delicious, my children claim you can’t taste the zucchini at all, making this the perfect recipe for using up lots of extra zucchini from the summer garden!

This recipe also takes advantage of sourdough discard- adding it to the wet ingredients gives a slight tang to the final product.  

For more yummy chocolate sourdough recipes, try my sourdough banana bread, chocolate chip croissant loaf, or chocolate chip dutch oven bread.

Why You’ll Love These Easy Muffins

• Economical:  Don’t let your zucchini go to waste!  Make a bunch of these muffins and store them in an airtight container to eat later. This recipe uses up a LOT of zucchini, and the kids don’t mind! 
• Delicious: Tender, flavorful, and moist, these sourdough zucchini muffins were gobbled up quickly.
• Easy: This simple recipe takes only a few minutes to whip up-no special steps, and you do NOT have to wring out the zucchini before using it. 

Ingredients

See the recipe card for the full ingredients!

• Wet Ingredients:  Avocado oil, eggs, sourdough starter, and milk make these muffins moist and succulent. 
• Dry Ingredients: All purpose flour, cocoa powder, baking soda and baking powder give these muffins height and flavor. 
• Flavors: Vanilla extract, sourdough discard, white and brown sugar, and miniature chocolate chips add unique flavor to this recipe.

Ingredient tips:  Set your eggs on the counter a few hours before making the muffins so they are at room temperature. 

Substitute avocado oil for other vegetable oil of your choice.  Make these muffins dairy free with almond milk.

What Is Sourdough Discard?

Sourdough discard is the leftover portion of flour and water that remains after the active sourdough has hit it’s peak and run out of food (flour and water). Discard is runny and flat, sour, and perfectly suited for baked goods like muffins!

How To Make The Best Sourdough Zucchini Muffins

• Step 1:  Wash the zucchini, and use a box grater to shred it. I used the medium grater, but you can finely shred the zucchini if desired. Do not blot, the damp zucchini will add moisture to the muffins. Line muffin tin with liners. Preheat oven to 425 degrees F. 
• Step 2: Add the flour, salt, baking soda, and baking powder into a large bowl and whisk well. 
• Step 3: In a separate bowl, add the brown sugar, white sugar, oil, eggs, vanilla, milk, and sourdough discard.  Use a spatula to mix all ingredients together until just combined.
• Step 4: Add half of the wet ingredients to the dry ingredients.  Mix until combined, then add the second half.  Do not over mix.
• Step 5:  Add the shredded zucchini and mini chocolate chips.  Mix just until combined.  
• Step 6: Line a muffin tin with cupcake liners.  Fill each liner 3/4 cup full. 
• Step 7:  Bake at 425 degrees F for 5 minutes.  Reduce temperature to 350 degrees F and cook for an additional 13-14 minutes or until a toothpick comes out dry with a few crumbs. Cool for 5 minutes.

Storage

Let the muffins cool completely and store in a ziplock bag for 3-4 days.  Place in a freezer safe, airtight container. Set the muffins in, making sure they don’t touch, and freeze for up to three months.

When ready to eat simply thaw, microwave and enjoy!

Tips

• Substitute chopped baker’s chocolate or regular chocolate chips if desired.
• For extra flavor use flaky sea salt in the dough and sprinkle some on top.
• Active sourdough starter can be substituted for the discard: just stir it down before adding to the recipe.
• Dairy free milk can be used in place of regular milk.

Faq’s