This post may contain affiliate links. Read our disclosure policy.
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!
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 Chocolate Cake Recipes
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
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.
* If using a glass pan, bake at 325°F for 35 to 40 minutes, or until a toothpick or cake tester comes out clean.
Photos by Ashley McLaughlin.
So delicious! Definitely needed an extra 10 mins or so but it was well worth it!
decided to actually measure all the ingredients for this recipe. the cake turned out absolutely delicious! it was def a crowd pleaser and my 5 yr old grandson, who helped me make it, had 3 pieces and licked his plate clean! excellent! thank you for this recipe. will def make it again in the near future.
Excellent , moist and chocolaty . Does not need icing. I used whipped cream but you don’t need any topping
Hi can I make this into a double layer 6”
Inch cake with chocolate frosting ?
Hi Tricia! We haven’t tried that, so I can’t say for sure! Let us know if you give that a try 🙂
I’m a pretty awful cook but I followed this recipe exactly and it came out amazing. I don’t think it needs the frosting. Thank you!
Can I use a food processor instead of grating and then following the rest of the recipe to remove moisture?
Hi Erica! Yes, using the shredding attachment/insert in your food processor should work just fine. Let us know what you think of this cake once you’ve given it a try! 🙂
delicious fun recipe! Thank you for including weight measurements!!
A terrific recipe! I brought it as dessert to a dinner party and it was a big hit. It took longer than 30 minutes in the oven. Next time I will probably make it 375-degrees. Thank you for the best recipe for zucchini chocolate I have found.
Since I only had Dutch cocoa in my kitchen I swapped the 1 teaspoon baking soda for 1 teaspoon baking powder and 1/2 teaspoon baking soda. Also, I live in Canada so I combined our all purpose flour with our cake & pastry flour to equal the protein content of US all purpose flour. It was amazing! Cake was fluffy, did not fall in the middle and was delish!
Bomb. Super moist, almost has a chocolate lava type flavor.
I have an abundance of spaghetti squash which I have already baked and shredded. Any chance I could sub this for the zucchini? And, what are your thoughts on baking this in a bundt pan?
Hi Suzanne! We haven’t tested this cake using anything but zucchini, and I’m honestly not sure if the moisture content would be the same. I recommend instead checking out Tessa’s recipe for Spaghetti Squash Spaghetti here! We have also only tested this recipe using an 8×8-inch metal baking pan, which may hold a different capacity of batter. Check out this pan conversion guide for more info on that, and just know that changing pan sizes like this will also mean adjusting the bake time. I hope this helps, Suzanne! Let us know how it goes 🙂
Easy to make and absolutely delicious !! I will definitely be making this often .
3rd time making this cake in 3 weeks, it is a the perfect chocolate cake, thank you!
Very delicious & moist
So happy to hear that, Susie!!
Family loves it and one of my daughter’s friends asked for recipe, which I copied for her. For glass 8×8 I did have to adjust temp (325) and time (a good 10 minutes more).
Hi Patty! So glad this is such a hit for your family and friends! 🙂
I used oat flour and dairy-free yogurt instead and it came out amazing!!!
Glad this was a hit, even with your substitutions, DD!!
Delish! Followed your instructions to the T. It was fluffy, moist, chocolate goodness. My hubby dislikes cake but we added a scoop of vanilla ice cream and it was wonderful, he said he’ll eat it again. My oven cooks a bit odd, so I had to cook mine about 10 min longer than the glass pan added time. I will make it again, but going to try some of your other recipes.
So happy to hear you enjoyed this recipe, Vicki! Can’t wait to hear what you make next 🙂
Can some left over baked cake be frozen for future consumption?
Hi Susan! We haven’t tried that, but it should be ok (though maybe not as pretty)! I’d recommend freezing individual slices on parchment for about 15-30 minutes, then wrapping each in plastic wrap and placing in an airtight container. Defrost in the fridge or on the counter and let come to room temp before enjoying.
I just left a comment, but forgot to rate it. It gets all 5 stars from me
I loved this Zucchini recipe. I have had breads made with zucchini and found them to be a little bland. I used a 8×8 Pyrex glass pan and sprayed it with some Pam. As another comment that was left, I passed on the icing and just used some powdered confectioners sugar more for presentation than for extra sweetness. It was a big hit and I enjoyed sharing it with several friends to enjoy. This will remain as a favorite go to recipe for me. Thank You
So happy you loved this recipe, Susan, and that it’s a go to! Thanks for sharing your tweaks as well 🙂
This is a great recipe! But this week I learned that it can also be a great base if needed for dairy and gluten free. I substituted plant based butter and sour cream, allergy friendly chocolate chips, and Bob’s Red Mill Gluten Free All Purpose flour. I did mini-cupcakes baked for 14 minutes. They were absolutely beautiful! Fluffy, moist, and so delicious. The zucchini helps bond the flour so they doesn’t fall apart, and it also removed grittiness that often comes along with gluten free products. Served them at a party and no one even realized it was zucchini cake. They were demolished so quickly and no one could believe they were really DF/GF.
Thanks so much for the yummy recipe! Especially love the weights that prevent user error on this recipe!
Thanks so much for sharing your findings! Glad this recipe worked perfectly with your substitutions 🙂
Cake is delicious…moist. You do not taste the zucchini at all. I did not have vanilla extract and used almond extract and it worked great!
So happy you enjoyed this recipe, Bonnie!
I came across this recipe when looking for a new recipe to bake with zucchini. I have made this twice now in 3 weeks. My family loves it. The chocolate flavor is so intense. The cake is so moist. It is an exceptional recipe and so easy to make. I love the fact that it is only an 8 x 8 one pan cake.
Amazing!! So happy to hear how much you’re enjoying this recipe and that it’s a family hit! Thanks for the comment, Janet 🙂
I have made this delicious cake for multiple family gatherings this summer and it has always been a hit! I double the recipe and bake it in a 9×13 cake pan, and I modified the recipe slightly – I use 275 g. sugar instead of 400 g., fat-free plain Greek yogurt instead of sour cream, and 2 eggs + 3 Tbsp. ground flax mixed with 9 Tbsp. water (allow to gel in the fridge for ~10 mins.) instead of 4 eggs and 2 egg yolks. My family likes desserts on the slightly less-sweet side, so I only use 170 g. of chocolate chips for a double recipe. I have gotten rave reviews every time 🙂
also i skip the icing because i don’t think it’s necessary – even with a reduced amount of sugar, this cake is plenty sweet! it is very yummy served with a spoonful of plain Greek yogurt and a few extra chocolate chips sprinkled on top!
So happy to hear your substitutions worked well, thanks for letting us know!