Irresistible Gluten Free Zucchini Brownies

Here are my gluten-free zucchini brownies, with a fudgy chocolate base packed with shredded zucchini, and topped with a sweet chocolate frosting that makes them taste like pure dessert.

These brownies are my go-to recipe when I have extra zucchini from the garden and want to sneak some veggies into a treat. The zucchini keeps them incredibly moist, and no one ever guesses there’s a green vegetable hiding inside!

What Kind of Zucchini Should I Use?

Any type of zucchini will work great in these brownies, whether you’ve got dark green, light green, or even yellow summer squash from your garden. Medium-sized zucchini tend to be the best choice since they’re tender and have fewer seeds than the giant ones you might find late in the season. Don’t worry about peeling your zucchini – the skin is thin and will blend right into the brownies, plus it adds extra nutrients and moisture. When you grate it, use the large holes on a box grater, and here’s the key: don’t squeeze out the liquid like you would for savory recipes, because that moisture is what makes these brownies so fudgy.

Options for Substitutions

These brownies are pretty forgiving when it comes to swaps, so here are some options if you need to make changes:

• Gluten free flour blend: If you’re not avoiding gluten, regular all-purpose flour works perfectly here. Use the same amount and follow the recipe as written.
• Vegetable oil: You can swap this with melted coconut oil, canola oil, or even melted butter if that’s what you have on hand.
• Granulated sugar: Coconut sugar or light brown sugar will work, though they’ll give the brownies a slightly different flavor and color.
• Almond milk: Any milk works here – regular dairy milk, oat milk, soy milk, or whatever you prefer. The amount stays the same.
• Semi-sweet chocolate chips: Dark chocolate chips, milk chocolate chips, or even chopped chocolate bars all work great. Pick whatever suits your taste.
• Zucchini: Don’t skip the zucchini – it’s what makes these brownies so moist and fudgy. There’s really no good substitute for it in this recipe.

Watch Out for These Mistakes While Baking

The biggest mistake when making zucchini brownies is squeezing out all the moisture from your grated zucchini – you actually want to keep it undrained since that liquid helps create a fudgy texture and prevents dry, crumbly brownies.

Another common error is overbaking, so start checking your brownies at the 25-minute mark with a toothpick inserted in the center, which should come out with just a few moist crumbs, not completely clean.

When making the frosting, avoid overheating the chocolate in the microwave by stopping every 15 seconds to stir, as burnt chocolate will turn grainy and ruin your frosting.

Finally, resist the urge to cut into these brownies right away – letting them cool completely allows the frosting to set and makes slicing much cleaner, giving you those nice, neat squares instead of a crumbly mess.

What to Serve With Zucchini Brownies?

These brownies are pretty rich and chocolatey on their own, so I love serving them with a big scoop of vanilla ice cream to balance out the sweetness. A cold glass of milk is always a winner too, especially if you’re going for that classic brownie experience. If you’re serving these at a party or gathering, they pair nicely with fresh berries like raspberries or strawberries, which add a little tartness that cuts through the chocolate. You could also whip up some fresh whipped cream on the side for people who want an extra creamy topping without going full ice cream.

Storage Instructions

Store: Keep your zucchini brownies in an airtight container at room temperature for up to 3 days, or in the fridge for up to a week. The fridge actually helps them stay extra moist because of all that zucchini! Just let them sit out for a few minutes before eating if you prefer them at room temperature.

Freeze: These brownies freeze really well, which is great when you want to hide them from yourself! Wrap individual pieces in plastic wrap, then store in a freezer bag for up to 3 months. You can also freeze the whole pan if you prefer.

Thaw: Let frozen brownies sit at room temperature for about 30 minutes, or thaw them overnight in the fridge. If you’re impatient like me, you can microwave individual pieces for about 15-20 seconds for a warm, fudgy treat.

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 3200-3400
• Protein: 30-38 g
• Fat: 155-170 g
• Carbohydrates: 455-480 g

Ingredients

For the brownies:

• 2 cups gluten-free flour blend (King Arthur Measure for Measure)
• 2/3 cup cocoa powder
• 2 tsp baking soda
• 1/2 tsp salt
• 1/2 cup oil
• 3/4 cup granulated sugar
• 1 egg (room temperature)
• 2 tsp vanilla extract
• 1/2 tsp espresso powder
• 2.5 cups zucchini (finely shredded and squeezed dry)

For the frosting:

• 1.5 cups semi-sweet chocolate chips
• 1/3 cup almond milk
• 3 tbsp butter (melted and cooled)
• 1.5 tsp vanilla extract
• 1.5 cups icing sugar

Step 1: Prepare Pan and Mix Dry Ingredients

• 2 cups gluten-free flour blend
• 2/3 cup cocoa powder
• 2 tsp baking soda
• 1/2 tsp salt

Preheat your oven to 350°F and grease a 9×13 inch baking dish (or 8×8 inch for thicker brownies).

While the oven heats, whisk together the gluten-free flour blend, cocoa powder, baking soda, and salt in a large mixing bowl.

This ensures even distribution of the leavening agent and prevents cocoa lumps in your brownies.

Step 2: Prepare Zucchini and Combine Wet Ingredients

• 1/2 cup oil
• 3/4 cup granulated sugar
• 1 egg
• 2 tsp vanilla extract
• 1/2 tsp espresso powder
• 2.5 cups zucchini

While the oven preheats, finely shred your zucchini and squeeze it very dry using a clean kitchen towel or paper towels—this step is crucial to prevent watery brownies.

In a separate bowl, whisk together the oil, granulated sugar, room temperature egg, 2 tsp vanilla extract, and espresso powder until well combined.

The espresso powder deepens the chocolate flavor without adding coffee taste, and I find it’s the secret weapon that makes these brownies taste more indulgent.

Step 3: Combine and Bake the Brownie Base

• dry ingredient mixture from Step 1
• wet ingredient mixture from Step 2
• 1.5 cups semi-sweet chocolate chips

Pour the wet ingredient mixture from Step 2 into the dry ingredients from Step 1 and stir until just combined—don’t overmix, as this can make brownies tough.

Fold in the prepared zucchini and chocolate chips gently until evenly distributed throughout the batter.

Spread the batter evenly into your prepared pan and bake for 25-30 minutes, until a toothpick inserted in the center comes out with just a few moist crumbs.

Let cool while you prepare the frosting.

Step 4: Make the Chocolate Frosting

• 1.5 cups semi-sweet chocolate chips
• 1/3 cup almond milk
• 3 tbsp butter
• 1.5 tsp vanilla extract
• 1.5 cups icing sugar

In a microwave-safe bowl, combine the chocolate chips, almond milk, melted and cooled butter, and 1.5 tsp vanilla extract.

Microwave in 35-45 second intervals, stirring between each interval, until the chocolate is completely melted and smooth.

Add the icing sugar and whisk vigorously until you achieve a silky, spreadable frosting—I like to whisk rather than stir because it incorporates air and creates a fluffier texture.

Step 5: Frost and Set

Spread or drizzle the chocolate frosting from Step 4 evenly over the cooled brownie base, working quickly before it sets.

Allow the frosting to cool and set completely at room temperature or in the refrigerator for 15-20 minutes before cutting into squares.

This ensures clean cuts and prevents the frosting from smudging.

Irresistible Gluten Free Zucchini Brownies

Delicious Irresistible Gluten Free Zucchini Brownies recipe with step-by-step instructions.

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 30 minutes mins

Total Time 45 minutes mins

Servings: 16 pieces

Calories: 3300

Ingredients Method

Ingredients

  

For the brownies

• 2 cups gluten-free flour blend (King Arthur Measure for Measure)
• 2/3 cup cocoa powder
• 2 tsp baking soda
• 1/2 tsp salt
• 1/2 cup oil
• 3/4 cup granulated sugar
• 1 egg (room temperature)
• 2 tsp vanilla extract
• 1/2 tsp espresso powder
• 2.5 cups zucchini (finely shredded and squeezed dry)

For the frosting

• 1.5 cups semi-sweet chocolate chips
• 1/3 cup almond milk
• 3 tbsp butter (melted and cooled)
• 1.5 tsp vanilla extract
• 1.5 cups icing sugar

Method

 

1. Preheat your oven to 350°F and grease a 9x13 inch baking dish (or 8x8 inch for thicker brownies). While the oven heats, whisk together the gluten-free flour blend, cocoa powder, baking soda, and salt in a large mixing bowl. This ensures even distribution of the leavening agent and prevents cocoa lumps in your brownies.
2. While the oven preheats, finely shred your zucchini and squeeze it very dry using a clean kitchen towel or paper towels—this step is crucial to prevent watery brownies. In a separate bowl, whisk together the oil, granulated sugar, room temperature egg, 2 tsp vanilla extract, and espresso powder until well combined. The espresso powder deepens the chocolate flavor without adding coffee taste, and I find it's the secret weapon that makes these brownies taste more indulgent.
3. Pour the wet ingredient mixture from Step 2 into the dry ingredients from Step 1 and stir until just combined—don't overmix, as this can make brownies tough. Fold in the prepared zucchini and chocolate chips gently until evenly distributed throughout the batter. Spread the batter evenly into your prepared pan and bake for 25-30 minutes, until a toothpick inserted in the center comes out with just a few moist crumbs. Let cool while you prepare the frosting.
4. In a microwave-safe bowl, combine the chocolate chips, almond milk, melted and cooled butter, and 1.5 tsp vanilla extract. Microwave in 35-45 second intervals, stirring between each interval, until the chocolate is completely melted and smooth. Add the icing sugar and whisk vigorously until you achieve a silky, spreadable frosting—I like to whisk rather than stir because it incorporates air and creates a fluffier texture.
5. Spread or drizzle the chocolate frosting from Step 4 evenly over the cooled brownie base, working quickly before it sets. Allow the frosting to cool and set completely at room temperature or in the refrigerator for 15-20 minutes before cutting into squares. This ensures clean cuts and prevents the frosting from smudging.