Double Chocolate Zucchini Muffins

These Double Chocolate Zucchini Muffins are rich, fudgy, and incredibly moist, with plenty of chocolate packed into every bite. Freshly grated zucchini keeps the muffins soft and tender without making them taste like vegetables, while cocoa powder, espresso powder, mini chocolate chips, and chopped dark chocolate give them a deep chocolate flavor. They’re an easy way to use up summer zucchini and are just as good for breakfast as they are for dessert!

Why You’ll Love These Double Chocolate Zucchini Muffins

• Incredibly moist. Fresh zucchini adds plenty of moisture and keeps the muffins soft for days.
• Loaded with chocolate. Cocoa powder creates the chocolate base, while mini chocolate chips and chopped dark chocolate give you pockets of melted chocolate throughout.
• No mixer needed. Everything comes together with a couple of bowls, a whisk, and a rubber spatula.
• Perfect for zucchini season. If your garden or farmers market haul has left you with more zucchini than you know what to do with, these muffins are the answer.
• Easy to freeze. Make a batch now and stash a few away for later.

Ingredient Notes

Zucchini: Freshly grated zucchini is the secret to the incredibly moist texture of these muffins. There’s no need to peel it first. For this recipe, don’t aggressively squeeze the zucchini dry—the moisture is part of what makes the muffins so soft.

Cocoa powder: Natural unsweetened cocoa powder gives these muffins their rich chocolate flavor and works with the baking soda to help the muffins rise.

Espresso powder: Just ½ teaspoon enhances the chocolate without making the muffins taste like coffee. It’s a small addition that makes the cocoa and dark chocolate taste even richer.

Brown and granulated sugar: Using both gives you the best of both worlds: granulated sugar provides sweetness and structure, while brown sugar contributes extra moisture and a subtle caramel flavor.

Neutral oil: Oil keeps these muffins exceptionally moist and tender, even after they’ve cooled. Avocado, canola, or vegetable oil will all work well.

Chocolate: Mini chocolate chips distribute little pockets of chocolate throughout the batter, while chopped dark chocolate creates larger, melty pieces. Using both makes these truly double chocolate muffins.

Tips for the Best Chocolate Zucchini Muffins

Don’t overmix the batter. Once you add the wet ingredients to the dry ingredients, fold just until everything comes together. Overmixing can make muffins dense or tough.

Grate the zucchini finely. A standard box grater works perfectly. Finely grated zucchini practically melts into the muffins as they bake.

Measure your flour accurately. For the most consistent results, I always recommend using a digital kitchen scale. Too much flour can take these muffins from moist and fudgy to dry.

Save some chocolate for the tops. A few pieces of chocolate sprinkled over each muffin before baking give them that bakery-style finish.

Check them early. Start checking around 18 minutes. A toothpick should come out with a few moist crumbs attached. If you hit melted chocolate with your toothpick, that doesn’t mean the muffins are underbaked!

Frequently Asked Questions

Can you taste the zucchini?

No! The zucchini has a very mild flavor and practically disappears into the chocolate batter as the muffins bake. Its main job is to add moisture and tenderness.

Do I need to peel the zucchini?

No. The zucchini skin is tender enough to leave on, and once grated and baked into the chocolate batter, you’ll barely notice it.

Should I squeeze the water out of the zucchini?

You don’t want to squeeze it completely dry. The natural moisture in the zucchini helps create the soft texture of these muffins. If your zucchini is exceptionally watery, you can lightly blot it with a paper towel, but avoid wringing out all of the liquid.

Can I leave out the espresso powder?

Absolutely. The espresso powder simply deepens the chocolate flavor and shouldn’t make the muffins taste like coffee. If you don’t have any, you can leave it out.

Can I use only chocolate chips?

Yes. If you don’t have a chocolate bar to chop, you can replace the 60 grams of chopped dark chocolate with another 60 grams of chocolate chips.

Storage & Freezing

Store leftover Double Chocolate Zucchini Muffins in an airtight container at room temperature for up to 2–3 days. For longer storage, refrigerate them for up to 5 days and bring them back to room temperature before serving.

To freeze, allow the muffins to cool completely and place them in a freezer-safe container or bag. Freeze for up to 2 months. Thaw individual muffins at room temperature or gently warm them in the microwave before serving.

My Favorite Baking Tools for This Recipe

Here are a few of my favorite baking essentials that make these Double Chocolate Zucchini Muffins easy to prep and bake. I’ve linked the tools I personally recommend below so you can find everything in one place.

As an Amazon Associate, I may earn a small commission from qualifying purchases made through these links, at no additional cost to you. Thank you for continuing supporting Bonia Bakery!

1. Digital Kitchen Scale – My favorite way to measure ingredients accurately and get consistent results every time.
2. 12-Cup Muffin Pan – A standard muffin pan is all you need for perfectly sized muffins.
3. Paper Muffin Liners – Make cleanup easy and help the muffins release effortlessly.
4. Box Grater – Perfect for finely grating the fresh zucchini.
5. Mixing Bowls – You’ll need two large bowls for mixing the wet and dry ingredients separately.
6. Silicone Spatula – Great for gently folding the batter together without overmixing.
7. Cooling Rack – Helps the muffins cool evenly without trapping excess moisture underneath.
   

Double Chocolate Zucchini Muffins

Yield: 12 muffins
Prep Time: 15 minutes
Bake Time: 18–22 minutes
Total Time: About 40 minutes

Ingredients

• 1½ cups grated zucchini
• 180g all-purpose flour
• 25g natural unsweetened cocoa powder
• 1¼ teaspoons baking soda
• ¼ teaspoon baking powder
• ½ teaspoon kosher salt
• ½ teaspoon espresso powder
• 100g granulated sugar
• 50g light brown sugar
• 120g neutral oil
• 1 large egg
• 2 teaspoons vanilla extract
• 60g mini chocolate chips
• 60g chopped dark chocolate
• Flaky sea salt, optional, for topping

Instructions

1. Prepare the oven and pan. Preheat the oven to 375°F (190°C). Line a 12-cup muffin pan with paper liners or lightly grease with nonstick baking spray. Set aside.
2. Combine the dry ingredients. In a large mixing bowl, whisk together the all-purpose flour, cocoa powder, baking soda, baking powder, kosher salt, and espresso powder until evenly combined.
3. Mix the wet ingredients. In a separate large bowl, whisk together the granulated sugar, light brown sugar, neutral oil, egg, and vanilla extract until smooth and well combined. Fold in the grated zucchini.
4. Make the batter. Pour the wet ingredients into the bowl of dry ingredients. Using a rubber spatula, gently fold everything together until just combined, being careful not to overmix. A few small streaks of flour are okay.

1. Add the chocolate. Fold in the mini chocolate chips and chopped dark chocolate, reserving a small handful of each for topping.
2. Fill the muffin pan. Using a large cookie scoop or ice cream scoop, divide the batter evenly among the prepared muffin cups, filling each about ¾ full. Sprinkle the reserved chocolate over the tops and finish with a tiny pinch of flaky sea salt, if desired.
3. Bake. Bake for 18–22 minutes, or until the tops are domed and set and a toothpick inserted into the center comes out with a few moist crumbs. Melted chocolate on the toothpick is perfectly fine.
4. Cool and serve. Allow the muffins to cool in the pan for 5 minutes before transferring them to a wire rack to cool completely. Enjoy warm or at room temperature.