Fudgy Zucchini Brownies

published Jul 20, 2022
Zucchini Brownies Recipe

These fudgy and decadent brownies are made with a triple dose of chocolate and a super summer-y secret ingredient.

Makes16 brownies

Prep20 minutes

Cook30 minutes to 35 minutes

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A photo of a single square zucchini brownie on a piece of wax paper.
Credit: Kayla Hoang

Deeply fudgy and perfectly moist, these brownies are made with a triple dose of chocolate and a super summer-y, secret ingredient: zucchini! Zucchini, while delicious in savory contexts, also works wonders in baked goods. It adds moisture and tenderness, and its flavor can either be played up, such as in a carrot cake-like context, or made subtle (almost undetectable), such as in chocolate zucchini bread or these delightfully decadent brownies. 

You’ll likely find that many zucchini brownie recipes often omit eggs (using chemical leaveners in its place for lift), are oil-based, and rely on a combination of the excessive amount of moisture from the zucchini and cocoa powder to make it chocolate-y, all of which can lead to a too wet, cakey, somewhat bland end product that dries out too quickly. I opt for a more classic route towards baking a flavorful, fudgy brownie that stays moist for days, making a few tweaks along the way to utilize in-season zucchini. 

How to Make Zucchini Brownies 

  • Melt butter (hello, flavor!) and chocolate together. 
  • Add espresso powder to emphasize the chocolate flavor and vanilla extract to round it out. 
  • Whisk a combination of granulated and light brown sugar into the chocolate mixture, followed by an egg. The light brown sugar contributes to the fudginess of the brownies as well as provides a caramel undertone. 
  • Add shredded zucchini that has been wrung out to rid of excess moisture (goodbye, overly wet brownies!) and whisk. 
  • Finish the batter with cocoa powder, salt, flour, and chocolate chunks for good measure and bake to yield supremely fudgy brownies ready to be topped with a cold scoop of vanilla ice cream.
Credit: Kayla Hoang

What Does Zucchini Replace in Baking?

Zucchini, similarly to bananas, can sometimes be used to replace eggs or act as the main source of liquid in a batter. However, because zucchini doesn’t provide structure or fat in the way that eggs do in brownies, this recipe utilizes a combination of the two to yield the best results. 

What Size Zucchini Is Best for Baking?

For this recipe, you need 11 ounces of zucchini (before trimming). A medium to medium-large sized zucchini is typically perfect for this, but two smaller zucchini can be used instead, as long as it adds up to 11 ounces. 

Do You Peel Zucchini for Baking?

The zucchini don’t need to be peeled, thanks to its thinner, delicate skin.

Zucchini Brownies Recipe

These fudgy and decadent brownies are made with a triple dose of chocolate and a super summer-y secret ingredient.

Prep time 20 minutes

Cook time 30 minutes to 35 minutes

Makes 16 brownies

Nutritional Info

Ingredients

  • 1

    large egg

  • Cooking spray

  • 8 tablespoons

    (1 stick) unsalted butter

  • 4 ounces

    bittersweet chocolate

  • 1 teaspoon

    vanilla extract

  • 1/2 teaspoon

    espresso powder (optional)

  • 11 ounces

    zucchini (2 small or 1 large)

  • 2/3 cup

    granulated sugar

  • 1/2 cup

    packed light brown sugar

  • 1/2 cup

    unsweetened cocoa powder

  • 1 1/4 teaspoons

    kosher salt

  • 2/3 cup

    all-purpose flour

  • 4 ounces

    semi-sweet chocolate or chocolate chunks

Instructions

  1. Place 1 large egg on the counter and let come to room temperature, 30 to 45 minutes. Meanwhile, arrange a rack in the middle of the oven and heat the oven to 350°F. Coat a 9x9-inch baking pan with cooking spray, then line with parchment paper so that it hangs over two sides of the pan. Lightly coat the parchment with cooking spray. (Alternatively, you can use an 8x8-inch baking pan for taller brownies.)

  2. Fill a medium saucepan with about 3 inches of water and bring to a boil over high heat. Meanwhile, cut 1 stick unsalted butter into 8 pieces and place in a medium heatproof bowl. Coarsely chop 4 ounces bittersweet chocolate and add to the bowl.

  3. Reduce the heat so the water maintains a simmer. Set the bowl onto the saucepan (make sure the bottom isn't touching the water) and heat, stirring occasionally, until the mixture is melted and smooth, about 5 minutes. Remove the bowl from the saucepan. (Alternatively, microwave the butter and chocolate together in a medium microwave-safe bowl in 30-second intervals, stirring between each, until melted, 1 to 1 1/2 minutes total.)

  4. Add 1 teaspoon vanilla extract and 1/2 teaspoon espresso powder and whisk to combine. Let cool until the bowl is just warm to the touch, 3 to 5 minutes. Meanwhile, trim the ends off 11 ounces zucchini. Grate on the large holes of a box grater (about 1 1/2 cups). Transfer to a clean kitchen towel or double layer of paper towels and squeeze out the excess moisture. Once squeezed, you should have about 1 cup zucchini. Place the zucchini on a cutting board and coarsely chop.

  5. Add 2/3 cup granulated sugar and 1/2 cup packed light brown sugar to the chocolate mixture and whisk until combined and no clumps of sugar remain. Add the egg and vigorously whisk until very well combined and the batter is every so slightly thickened, about 2 minutes.

  6. Add the zucchini and whisk until well combined and any clumps of zucchini are broken up, about 30 seconds. Sift 1/2 cup unsweetened cocoa powder onto the chocolate mixture. Add 1 1/4 teaspoons kosher salt and whisk until fully incorporated. Add 2/3 cup all-purpose flour and fold until just combined. Some dry spots are okay.

  7. If using bar semi-sweet chocolate, coarsely chop 4 ounces into chunks (about 2/3 cup). Add to the batter and fold until just evenly distributed. Don’t overmix. Pour into the baking pan and spread into an even layer.

  8. Bake until the brownies are slightly puffed and a tester comes out with just a few moist crumbs, 25 to 30 minutes for a 9-inch pan, or 27 to 35 minutes for an 8-inch pan. Place the pan on a wire rack and let cool 10 minutes. Grasping the excess parchment, remove the brownie slab and place on the rack. Let cool completely before cutting, about 1 hour. Use a hot, dry knife (run it under the hottest tap water and then carefully dry it with a towel) to cut the slab into 16 pieces, wiping the knife between cuts.

Recipe Notes

Semi-sweet chocolate substitute: Semi-sweet chocolate chunks can be used instead of chopping a bar of chocolate.

Make ahead: The brownies can be made up to 1 day in advance and stored in an airtight container or wrapped well at room temperature.

Storage: The brownies can be stored in an airtight container at room temperature for up to 4 days.