Tessa’s Recipe Rundown
Taste: Ultra chocolaty! I doubt any kids would guess there’s a vegetable involved here.
Texture: Rich, fudgy, and moist.
Ease: Super quick and easy. No mixer, no assembling, no decorating.
Pros: Simple summer treat!
Cons: None 🙂
Would I make this again? Absolutely, all season long.
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We’re about to head into the height of zucchini season, which is just one of the many reasons you’ll adore this Chocolate Zucchini Cake.
I love getting fresh zucchini from the farmer’s market all summer long. It’s one of those veggies that’s so easy to cook and bake with. You can find a million ways to get creative whether you’re going savory or sweet. And it doesn’t take nearly an hour to cook like root veggies.
Adding zucchini to cake happens to be one of my favorite ways to use the stuff. I also enjoy a good zucchini bread, like this Lemon Yogurt Zucchini Bread.
I love snack cakes like this recipe because they’re just one layer, and there’s no assembly or decorating required. They’re also super easy to transport. You don’t even need an electric mixer for the batter or the icing here!
That makes this recipe perfect for bringing to a summer potluck or BBQ. Especially if you have an abundance of zucchini to use up!
I find many chocolate zucchini cakes to be kind of bland and a little dry. Read my tips below for getting a super rich and fudgy cake with tons of chocolate flavor.
This might just become your new favorite zucchini recipe!
Sprinkle of Science
How to Make Moist Chocolate Zucchini Cake
The Best Cocoa Powder for Chocolate Cake
Cocoa powder lends more chocolate flavor than melted chocolate. But it can also zap some moisture, so read my tips below for how to make sure your cake is nice and tender and moist. This recipe uses natural unsweetened cocoa powder (not Dutch process cocoa powder). Learn more about cocoa powder here.
For best results, weigh your cocoa powder and flour to ensure you don’t over-measure. This will result in a dry cake. If you don’t have a digital kitchen scale, then use the spoon-and-level method.
How to Shred Zucchini for Cake (IMPORTANT!)
To avoid gummy, dense, or unbaked Chocolate Zucchini Cake, it’s important to remove as much excess water from the zucchini as possible.
- Start by washing the zucchini and trimming the ends. Grate using the big holes of a box grater. Scoop up the shredded zucchini and place in a strainer or colander. Move on to prepare the rest of the ingredients and batter for the recipe.
- Once you’re ready to add in the zucchini, wrap it in a clean towel or paper towels and give it a very tight squeeze with your hands to wring out excess water. Do this a few times. If your hands aren’t quite strong enough, you can also press the zucchini inside a potato ricer or hand-held citrus squeezer. This is super effective at getting rid of water.
- Once you fold in the zucchini to the batter, stir gently until JUST combined. Over-mixing can cause a tough or gummy texture.
Why Use Butter AND Oil in a Cake?
- I find this provides the best of both worlds.
- You get the wonderful flavor from the butter and the moist texture from the oil.
- This is because oil is a liquid at room temperature so it gives your palate the sensation of moisture.
- Learn more about Butter vs. Oil in Baking here.
How to Bake a Moist & Fudgy Chocolate Cake
- In addition to the tips above, using ingredients like brown sugar, full-fat sour cream, and an extra egg yolk all help to add richness and moisture to this cake.
- That’s because these ingredients both tenderize and draw and hold onto moisture.
- You can learn more about how baking ingredients work in my Magic of Baking online class.
Can I Substitute the Sour Cream?
You can use full-fat plain yogurt instead!
What Type of Chocolate Chips Should I Use?
I used semi-sweet chocolate chips, but you could experiment with milk chocolate chips, mini chocolate chips, or even white chocolate chips, if you prefer.
Is it Better to Bake a Cake in a Glass or Metal Pan?
- This recipe is best baked in an 8-inch metal baking pan.
- Metal conducts heat more quickly and efficiently than glass or ceramic so you won’t have any issues with an under-baked center.
- If you must use glass or ceramic, reduce the baking temperature to 325°F and increase the baking time by 5 to 10 minutes.
- Learn more about Glass vs. Metal Baking Pans in my article here.
Frosting for Zucchini Cake
I used a simple icing for this Chocolate Zucchini Cake recipe, but you could also use my cream cheese frosting or even this chocolate frosting.
Can I Double this Recipe?
Yes! Double all ingredients, bake in a 9 by 13-inch pan, and add about 5 to 10 minutes to the baking time. If using glass, see note above.
How Long Does Chocolate Zucchini Cake Last?
This Zucchini Cake can be stored in an airtight container at room temperature for up to 4 days.
Can You Freeze Chocolate Zucchini Cake?
- Freeze individual slices on parchment paper for about 15-30 minutes, then wrap each in plastic wrap and place in an airtight container.
- Defrost in the fridge or on the counter and let come to room temperature before enjoying.
- I recommend freezing the cake unfrosted.
More Recipes You’ll Love:
- Chocolate Zucchini Bread
- Best Ever Chocolate Cake
- Chocolate Bundt Cake
- Easy Chocolate Sheet Cake
- Flourless Chocolate Cake
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Easy Chocolate Zucchini Cake
Ingredients
For the cake:
- 1 cup plus 2 tablespoons (143 grams) all-purpose flour, measured correctly
- 1/2 cup (43 grams) unsweetened cocoa, measured correctly
- 1 cup (200 grams) light brown sugar
- 1 teaspoon salt
- 1 teaspoon baking soda
- 4 tablespoons (57 grams) unsalted butter, melted
- 1/4 cup fresh vegetable oil
- 1/2 cup (120 grams) full fat sour cream or plain whole milk yogurt, at room temperature
- 2 large eggs plus 1 egg yolk, at room temperature
- 2 teaspoons vanilla extract
- 1 cup (136 grams) shredded zucchini, from about 1 medium zucchini
- 1 cup (170 grams) semisweet chocolate chips
For the icing:
- 1/2 cup (63 grams) powdered sugar, sifted
- 1 tablespoon milk
Instructions
Make the cake:
- Preheat the oven to 350°F. Line an 8 by 8-inch metal baking pan* with parchment paper then spray with nonstick cooking spray.
- In a large bowl, whisk together the flour, cocoa, sugar, salt, and baking soda.
- In a small bowl, whisk together the melted butter, oil, sour cream, eggs, egg yolk, and vanilla extract.
- Make a well in the center of the dry ingredients and pour in the wet ingredients. Stir until a few streaks of flour remain. Squeeze out any additional moisture from the shredded zucchini before adding to the batter (see recipe post for tips on reducing excess moisture, which will create a gummy cake texture). Add in the chocolate chips. Stir until just barely combined.
- Pour the batter into the prepared pan and bake for 30 minutes or until a toothpick or cake tester comes out clean. If your cake sinks slightly in the middle, that's normal because it's so moist and rich!
- Let cool completely.
Make the frosting:
- In a medium bowl, stir together the sugar and milk with a fork until smooth and thick but pourable. Drizzle all over the cake. Let set before serving.
- Cake can be stored in an airtight container at room temperature for up to 4 days.
Recipe Notes
Photos by Ashley McLaughlin.
Can you bake this in a Bundt pan?
Hi Kelly! We haven’t tested baking this cake in a Bundt pan, so I can’t say for sure how well that will work. The volume of your Bundt pan may be different from the recommended pan here, so you may need to adjust your bake time. Additionally, removing the cake from the Bundt pan might be more challenging. For more information on this, check out Tessa’s article ‘How to Prevent Bundt Cakes from Sticking’ here. However, feel free to experiment and let us know how it goes. Happy baking!
The cake is a hit, but how do you get your icing so white? Mine is a glassy look and blends in.
Hi Heidi! So glad to hear that you enjoyed this cake! It sounds like you needed a little more powdered sugar. Different brands sometimes absorb different amounts of liquid, so feel free to add a little more powdered sugar next time (or reduce the amount of liquid slightly), until your icing is thick but still pourable. I hope that helps 🙂
I’ve made this before, basically because I grew too many zucchinis however, everyone loved it, even the non zucchini people, could not taste zucchini. So easy, making another one now for a picnic in the park tomorrow. Love it👍
Delicious birthday cake
Can i use spaghetti squash instead of zucchini?
Hi Michelle! We haven’t tried that so we can’t say for sure! Let us know how it goes if you give that a try 🙂
Needed another ten minutes and quite oily, not sure why. Good taste though.
Hi Elle! I’m sorry to hear that your cake didn’t turn out as it should! Without having baked alongside you, it can be tricky to pinpoint exactly what went wrong – but here are a few common issues:
– Your oven might be running a little cool. Do you have an oven thermometer to check that? Check out Tessa’s article here about ovens, full of tips!! If you don’t have an oven thermometer to ensure your oven is at the temperature it says it is, invest in one now! They are inexpensive and really help your baking so much! This oven thermometer is one of Tessa’s favorites.
– Was your cake baked in a metal pan? Glass and ceramic pans often take longer to bake through, and can leave the texture a little off. Learn more about this in Tessa’s Glass vs. Metal Pans article here.
– Check out more tips for this recipe (including squeezing out your zucchini super thoroughly, weighing your ingredients, and the recommended type of cocoa powder to use) in the Tip Box, above the recipe.
I hope something here helps, Elle, and I hope you’ll give this recipe another try sometime – it really is fantastic! Happy baking 🙂
Followed it to the letter except for using nonfat Fage Greek yogurt instead of sour cream. Absolutely delicious!
This looks so delicious but Can you use fine sugar instead of brown sugar?
Hi Anne! Feel free to experiment as you wish, but Tessa developed this recipe to maximize moistness, so light brown sugar assists because it carries more moisture than white sugars. Let us know how it goes if you give that a try!
Made the cake, needed an extra 10 minutes. Very moist, however we found it very rich and sweet.