Rich and decadent Chocolate Zucchini Brownies are made extra moist with grated zucchini. Topped with a decadent fudge frosting, these fudgy brownies are easy to make in one bowl!

As much as we all love Roasted Zucchini as a side dish, let’s focus on some sweets. We love this Chocolate Chip Zucchini Bread and Zucchini Banana Bread. What’s your favorite zucchini recipe?
Why this Recipe is Best
If you’ve never added zucchini to your chocolate desserts before, you’re in for a treat. This recipe is the perfect way to use up any extra zucchini you have in your fridge, without making another loaf of zucchini bread.
- Grated zucchini makes chocolate brownies unbelievably moist.
- Works well with fresh OR frozen zucchini.
- Topped with dreamy chocolate fudge frosting!
Bonus: these are so easy to make! The brownie batter comes together in one mixing bowl in a matter of minutes.
If you LOVE frosted brownies, you’ve got to try them with zucchini too.
Ingredient Notes
- Cocoa powder. A good quality chocolate cocoa powder, such as Hershey’s Special Dark or Ghirardelli is best.
- Vegetable oil. A higher fat to flour ratio keeps these brownies incredibly moist and fudgy.
- Unsalted butter. If using salted butter, omit the extra kosher salt in the recipe.
- Vanilla extract. As always, choose a pure vanilla and not imitation vanilla. Our homemade vanilla extract is easy to make, and affordable too!
- Shredded zucchini. See instructions below for the best way to grate zucchini. If using frozen zucchini, be sure to squeeze out the excess moisture, THEN measure the amount needed. Choose smaller zucchinis if possible as they retain much more moisture than those overside large zucchini (which tend to be more dry and perfect for freezing).
How to Grate Zucchini
The first step to making chocolate brownies with zucchini is to grate the zucchini well. After washing your zucchini, cut off the stems. (Peeling is optional but not necessary.)
If you have extra large zucchini, scoop out those big seeds from the middle.
A food processor with a grater attachment is the easiest and fastest way to grate zucchini. Start the food processor and feed the zucchini in vertically while it’s running.
You can also grate it the old fashioned way with a big box grater: Hold the zucchini up against the grater placed over a large bowl. Run the zucchini down the side of the grater just like you would a block of cheese.
I don’t recommend using a fine microplane zester or a food processor with blades. Both will make the zucchini more pureed and watery than grated and it won’t work as well in the brownies.
Once your zucchini is grated, it’s time to bake some brownies!
Tips & Tricks
- Let the batter rest. The brownie batter will look very dry when it first comes together. This is normal. Let it sit for 10 minutes before pouring it to the baking dish. The moisture from the zucchini will release into the batter as it rests. Trust me!
- Cut brownies with a clean plastic knife. The plastic knife makes perfectly even cuts–no crumbling! Be sure to let the brownies cool completely before cutting them!
- Store tightly covered. At room temperature, these chocolate zucchini brownies stay good for 4 -5 days.
- Additions: Add some chocolate chips or walnuts pieces to the batter before baking for a delicious dreamy brownie.
- Try our chocolate chip frosted zucchini brownies for a delicious twist! Or give our zucchini cookies a try next!
Recipe FAQs
This recipe was tested in a 9 x 13 inch baking dish.
The batter is supposed to be quite dry before you add the zucchini. Stir in the zucchini then let it rest for 10 minutes and it’ll start to be softer and more workable.
You can use milk if you want but the frosting won’t be as thick and creamy. I highly recommend real heavy whipping cream here!
Double Chocolate Zucchini Brownies
These fudgy brownies are topped with a delicoius fudgy frosting.
It’s easy to make too! Combine melted butter with cocoa powder in a small bowl with a whisk. Add in powdered sugar, heavy cream and vanilla. Whisk until smooth.
Spread over cooled brownies. Cut into bars and enjoy!! You could also make a half batch of our creamy chocolate buttercream frosting. Or give our vanilla frosting recipe a try instead!
More Zucchini Recipes
- Chocolate Zucchini Bundt Cake: it’s as delicious as it looks!!
- Streusel Topped Zucchini Bread: the crunch on top makes this one epic bread!
- Zucchini Bundt Cake: this beauty is topped with a cinnamon glaze!
- Start the day off with these Zucchini Orange Muffins or this sweet Chocolate Zucchini Bread!
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Ingredients
For the Brownies:
- ½ cup vegetable oil
- 1 cup granulated sugar
- ½ cup light brown sugar packed
- 2 teaspoons vanilla extract
- 2 cups all-purpose flour
- ½ cup dark chocolate unsweetened cocoa powder
- 1 ½ teaspoon baking soda
- 1 teaspoon kosher salt
- 2 ½ cups finely shredded zucchini
For the Frosting:
- ¼ cup unsalted butter melted
- 5 Tablespoons dark chocolate unsweetened cocoa powder
- 2 cups powdered sugar
- 6 Tablespoons heavy whipping cream
- ½ teaspoon vanilla extract
Instructions
- Preheat oven to 350 degree F. Line a 13×9 baking dish with parchment paper. Set aside.
- For the brownies, in a large bowl, combine oil, sugars, and vanilla extract. Add in flour, cocoa powder, baking soda and salt. Stir together until well blended. The batter will be very dry, it’s okay!!
- Fold in shredded zucchini. Depending on the moisture of your zucchini, your batter may still be slightly dry. Let batter sit 10 minutes before pouring into baking dish.
- Bake for 25-30 minutes until cooked. Remove and cool completely before frosting.
- For the frosting, combine the melted butter with cocoa powder in a small bowl with a whisk. Add in powdered sugar, heavy cream and vanilla. Whisk until smooth. Spread over cooled brownies. Cut into bars and enjoy!!
Notes
- Let the batter rest. The brownie batter will look very dry when it first comes together. This is normal. Let it sit for 10 minutes before pouring it to the baking dish. The moisture from the zucchini will release into the batter as it rests. Trust me!
- Cut brownies with a clean plastic knife. The plastic knife makes perfectly even cuts–no crumbling! Be sure to let the brownies cool completely before cutting them!
- Store tightly covered. At room temperature, these chocolate zucchini brownies stay good for 4 -5 days.
- Additions: Add some chocolate chips or walnuts pieces to the batter before baking for a delicious dreamy brownie.
- Try our chocolate chip frosted zucchini brownies for a delicious twist!
Video
Nutrition
Don’t waste any zucchini ever again. Make Chocolate Zucchini Brownies covered in a fudgy ganache frosting instead!
Can I use regular cocoa instead of dark chocolate cocoa. I don’t have the dark chocolate cocoa