Here’s a gluten-free zucchini brownies recipe that hits all the right notes: deeply chocolate, moist and fudgy brownies topped with a light, fluffy peanut butter frosting and finished with a glossy chocolate glaze. The best part? You don’t need to grate the zucchini—just pulse it straight in a food processor with the wet ingredients, or follow the easy by-hand option. Dump the batter into a pan, bake, and enjoy.
Fudgy Gluten-Free Zucchini Brownies with Peanut Butter Frosting
Zucchini adds moisture and structure to baked goods, so it’s a perfect secret ingredient for brownies. These gluten-free brownies use all-purpose gluten-free flour and unsweetened cocoa powder to create a rich chocolate base that stays tender thanks to the zucchini. You’ll get a dense, fudgy crumb without any dryness or crumbliness.
Once baked and cooled, the brownies are covered with a decadent peanut butter frosting—creamy, slightly salty, and light enough to balance the chocolate. A simple melted chocolate glaze finishes the bars, creating a smooth, shiny top that slices cleanly. These come together quickly and make a great dessert for gatherings or an indulgent everyday treat.
I was gifted some zucchini and wanted to try something different and delicious. This recipe looked like it would fit that bill and it did!! I LOVE these brownies! I will definitely keep this recipe! Thank you!
—Erika
Let’s Make This Together!
(Below are step-by-step highlights. The full ingredient amounts and instructions are in the recipe card below.)
Magically easy zucchini prep
No grating required if you have a food processor. Just add zucchini, eggs, and melted butter and blend until smooth. If you don’t have a food processor, shred 3 cups of zucchini and mix by hand.
Add dry ingredients and blend
Combine sugar, cocoa, gluten-free flour, baking powder, and salt with the wet zucchini mixture and pulse until just combined.
More chocolate goodness and bake
Fold or pulse in chocolate chips, spread the batter in a greased pan, and bake until set but still fudgy. Cool completely before frosting.
Fluffy Peanut Butter Frosting
When the brownies are fully cooled, beat together creamy peanut butter, softened butter, powdered sugar, vanilla, and a pinch of salt. Start on low speed to combine, then beat on high briefly until the frosting is light and fluffy. Add a tablespoon of milk (or more as needed) to reach a spreadable consistency.
If you prefer, omit the peanut butter frosting and top the brownies with only the chocolate glaze or a simple chocolate buttercream. For a lighter presentation, a dusting of powdered sugar also works well.
Bonus Tips, Tricks, and Goodness
- If you don’t have a food processor, grate zucchini and measure 3 cups of shredded zucchini. There’s no need to peel the zucchini.
- To make a smaller batch, halve the recipe and bake in an 8″ or 9″ square pan for about 25–30 minutes.
- Using Dutch-processed cocoa will yield a deeper, darker chocolate flavor; natural unsweetened cocoa can be used instead.
- If you skip the peanut butter frosting, you can make a simple chocolate frosting by combining cocoa, melted butter, powdered sugar, and milk until spreadable and smoothing it over slightly warm brownies.
- For festive variations, swap the peanut butter topping for cream cheese frosting and add seasonal decorations.
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Pin it to your collection and try it later — these brownies are worth it.
Did you make this recipe? I love hearing from you! Leave a star rating and comment below the recipe card — feedback helps others and is much appreciated. -Melissa
Easy, Moist Gluten-Free Zucchini Brownies
Melissa ErdelacPin
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Ingredients
Zucchini Brownies
- 16 ounces zucchini (about 2 small), cut into chunks (about 4 cups)
- 6 tablespoons unsalted butter, melted
- 4 large eggs
- 2 teaspoons vanilla extract
- 1 ½ cups sugar
- ⅔ cup unsweetened cocoa powder (Dutch-processed preferred)
- ½ teaspoon baking powder
- ½ teaspoon salt
- 1 ¼ cups all-purpose gluten-free flour
- 1 cup chocolate chips
Peanut Butter Frosting
- ¾ cup creamy peanut butter
- ½ cup unsalted butter, softened
- 1 cup powdered sugar
- 1 teaspoon vanilla extract
- ½ teaspoon salt
- 1 tablespoon milk or non-dairy milk
Chocolate Glaze
- ¾ cup semisweet chocolate chips
- 4 tablespoons unsalted butter, cubed
Equipment
- Food Processor (or box grater for the by-hand method)
- 9×13 baking dish
- Offset spatula (optional)
Instructions
Zucchini Brownies:
- Preheat oven to 350ºF. Grease a 9×13″ pan and set aside.
- In a food processor, combine zucchini chunks, melted butter, eggs, and vanilla. Process until smooth. (If making by hand, shred zucchini and mix with the wet ingredients.)
- Add sugar, cocoa powder, baking powder, salt, and gluten-free flour. Process until just combined. Add chocolate chips and pulse a few times to disperse.
- Spread batter in the prepared pan and bake 30–35 minutes, until a toothpick comes out without wet batter. Cool completely in the pan.
Peanut Butter Frosting
- In a medium bowl, beat peanut butter, softened butter, powdered sugar, vanilla, and salt on low speed until combined. Scrape the bowl, then beat on high until smooth and fluffy, about 1 minute.
- Add milk and mix until the frosting reaches a spreadable consistency. Spread over cooled brownies.
Chocolate Glaze:
- Place chocolate chips and cubed butter in a microwave-safe bowl. Heat 30–60 seconds, stirring until smooth and combined.
- Pour the glaze over the frosting and smooth with a spatula. Chill 15 minutes to set before cutting into bars.
Notes
By Hand Method
If you don’t have a food processor, grate zucchini and measure 3 cups of shredded zucchini. Mix the shredded zucchini with melted butter, eggs, and vanilla, then add the remaining ingredients.
Recipe adapted from a classic zucchini brownie approach.