This gluten free chocolate zucchini cake is simply the richest, most moist chocolate cake ever. What else were you going to do with all that zucchini?
What makes this gluten free chocolate zucchini cake special (and so useful!)?
This cake is so rich, with deep chocolate flavor, and the zucchini keeps every dense, rich bite moist and tender without being “fluffy.”
Every solid recipe using at least a few cups of shredded zucchini is nothing short of a public service. Take this gluten free chocolate zucchini cake, for example.
It tastes approximately, well, nothing like zucchini. The garden veg is just a delivery system for moisture in each morsel of cake. The fudge frosting on top is a nice bonus, especially since you won’t believe how easy it is to make a chocolate frosting without powdered sugar!
The best gluten free chocolate zucchini cake recipe? Definitely!
- This one bowl chocolate zucchini cake is super easy to put together with dry ingredients whisked, then wet ingredients added and mixed
- It has incredible texture and taste, making for a rich chocolate cake with only cocoa powder, no melted chocolate in the batter.
- A healthy chocolate zucchini cake is an easy way to sneak in veggies, since you won’t taste the zucchini at all
- Finally, no one will know it’s gluten free, if they have that thing where they think that gluten free cakes are “only okay.”
Ingredients for my healthy chocolate zucchini cake recipe
How much zucchini does this gf chocolate zucchini cake use?
This cake makes good on 3 whole cups of grated zucchini and makes you happy that your husband planted 3 zucchini plants again this year even though you asked him to plant 2 at most. Very nicely. And then not so nice.
More chocolate gluten free zucchini cake ingredient notes
- Gluten free flour – I prefer Better Batter (always their classic rice flour-based blend) here, and be sure to measure by weight, not volume, for reliable results
- Unsweetened cocoa powder – I use Dutch-processed cocoa powder, which is treated to neutralize the natural acid in natural cocoa powder; if you use natural cocoa powder, just add 1/8 teaspoon baking soda to rebalance
- Salt – Brings out flavors and balances the sweetness
- Baking powder – A chemical leavener that is responsible for most of the rise in the cake
- Granulated sugar – A sweetener and a tenderizer; don’t cut back as it’s not an especially sweet cake at all!
- Light brown sugar – A sweetener and tenderizer, like granulated sugar, but adds depth of flavor and moisture from the molasses added to it
- Oil – The fat in this recipe is from a neutral, flavorless oil, that, together with cocoa powder, creates that deep chocolate flavor and mouthfeel
- Eggs – Eggs help bind the ingredients together and aid in the cake’s rise; yolks provide richness
- Vanilla extract – Bring out the chocolate flavor and adds depth
What you need to make this healthy chocolate cake recipe
You don’t need much equipment at all to make this zucchini cake. Beyond the ingredients in the recipe, the only equipment you need is:
- Mixing bowl and spoon
- Whisk to combine dry ingredients (or just a fork)
- 9-inch square (or round) baking pan
- Parchment paper to line the pan
- Spatula to scrape the batter into the baking pan and smooth it into an even layer
- An oven for baking
Tips for making the best gluten free chocolate zucchini cake
Don’t try to substitute the gluten free flour blend
When we’re baking gluten free with an “all purpose gluten free flour blend,” the blend always matters. I use and recommend Better Batter here, but any of the blends I discuss as all purpose gf blends on the blog (click that link in the previous sentence or in the recipe card where the flour blend is referenced) will work.
Don’t try using a single-ingredient flour, such as almond flour or coconut flour, as they only work in recipes that are designed to be made with them.
Shred your zucchini to a standard grate size
I find shredding zucchini to be easiest using a standard box grater, ideally one with a lid on the bottom, so it catches the shreds. Use the “coarse shred” size, which is usually the side of your grater with the largest repeating hole (as opposed to the slicer).
You can also shred your zucchini using a a food processor fitted with the shredder blade. If you’re going to use a food processor, then shred tons of zucchini, and store leftover in a freezer-safe zip top bag. Defrost, and bake!
Drain your zucchini of its liquid
Be sure to squeeze as much of the surface moisture from your shredded zucchini as you can. You can do this using a mesh nut milk bag or a tea towel (a kitchen towel with a flat weave)—just pile in the shredded zucchini and squeeze over the sink.
There will still be some moisture inside the vegetable, but since the amount of moisture in the vegetable can vary so much, squeezing out the moisture is the only way to make sure we’re all using the same ingredient.
Bake your gf zucchini cake on the middle rack
For even baking, and don’t forget to preheat your oven and gauge your oven’s temperature using a standalone oven thermometer that you replace frequently. Most ovens, including mine, run hot and out of calibration, which causes cakes to puff and then fall as they cool since they’re underbaked in the center.
Don’t overbake to keep your chocolate zucchini cake moist
This is a very moist, tender gf cake, so your cake tester inserted in the center won’t come out completely clean. Test doneness as described in the recipe: when the center of the cake springs back when pressed gently in the center and a tester comes out with a few moist crumbs attached.
Let your gf chocolate zucchini cake cool completely before frosting
Frosting a warm cake will cause your frosting, or even a light dusting of powdered sugar, to melt right into the cake. You’ll still taste the topping, but you won’t see it—and it will lose its texture.
How to make the chocolate fudge frosting
This chocolate frosting is completely optional here, but it’s such a good choice—and stays fresh in a sealed glass jar on the countertop for days. It’s made entirely without any sort of confectioners’ or powdered sugar, which makes it a nice option for a quick, fuss-free frosting. And it’s just so glossy and smooth!
All you do is blend granulated sugar with evaporated milk (not sweetened condensed milk, and just 2/3 cup, so you won’t need a whole can of evaporated milk) to dissolve the sugar and ensure the frosting isn’t grainy. Then, melt 4 ounces of chopped chocolate, and 4 tablespoons of unsalted butter, and blend them right in.
As you blend, the frosting will thicken to a thick pudding-like consistency, like magic. You’ll know the frosting is ready when you can turn your blender upside down and it won’t move.
More serving suggestions for this gf chocolate zucchini cake
I’d like to recommend that you enjoy a slice of this crazy delicious gluten free chocolate zucchini cake with some summer berries, like strawberries.
Since you’re only likely to be making this particular gluten free chocolate cake in the summertime, you should go all the way. Here are some more suggestions:
- Try a different frosting, like strawberry sauce or cream cheese frosting;
- Make a healthy birthday cake with frosting and colorful sprinkles
- Dust lightly with with powdered sugar after the cake is completely cool, and serve with a dollop of fresh whipped cream
- Replace the chocolate chips with a different flavor of chips, like butterscotch or peanut butter chips (just be sure your brand is GF).
How to store leftover gluten free zucchini cake
In testing this recipe, I made it so many times that I had an enormous backlog of cake in my kitchen. I ended up storing it, cut into bite-sized pieces, in sealed containers on the countertop for a full week. And it was only just beginning to taste a little dry on day 6.
Can I freeze gluten free chocolate zucchini cake?
Yes! For longer storage, you can freeze the whole, unfrosted cake, or freeze individual slices. Just wrap each tightly in freezer-safe wrap to avoid freezer burn, and defrost at room temperature. Frost before serving.
Gluten free chocolate zucchini cake: substitutions
Whenever I can, I like to provide you with as much information as possible on modifying this recipe to suit all of your individual dietary needs. These are educated guesses, though, since I haven’t actually made this recipe successfully in any way other than as it’s written in the actual recipe below.
About the dairy in this gf chocolate zucchini cake
The only dairy in the cake recipe is the buttermilk. If you’re dairy-free, you can replace dairy buttermilk with a combination of half plain nondairy yogurt (by volume) and half unsweetened nondairy milk (by volume).
If you can have dairy, and you’re out of buttermilk or just don’t want to buy it, try using plain kefir or the half-plain-yogurt-half-milk trick, just with dairy products.
The fudge frosting on top is made with evaporated milk and butter, though. If you’re dairy free, you can leave the fudge frosting out, or try using coconut evaporated milk (Nature’s Charm is the brand I’ve seen) and vegan butter (Melt and Miyoko’s Kitchen brands are my favorite).
If you’re dairy-free, be sure that the chocolate chips and bittersweet chocolate you’re using are dairy free.
Gluten free, egg free chocolate zucchini cake
Since this recipe calls for 3 whole eggs, which is in dangerous territory for replacing eggs (my upper limit for egg replacement is usually 2). But it’s worth trying one “chia egg,” which is just a tablespoon of ground chia seeds mixed with 1 tablespoon of cool water until it gels per chicken egg.
One chia egg per actual egg, please. No flax eggs, though, please, which adds an unwanted flavor.
Gluten free, vegan chocolate zucchini cake
Use the dairy free and egg free suggestions above, and use vegan sugars, made without use of bone char.
Gluten free chocolate zucchini cake without chocolate?
If you’d like a plainer version of this cake, without chocolate, there really isn’t a substitute for the chopped, melted chocolate and cocoa powder.
Instead, I have a recipe for gluten free zucchini cake with the most tender texture—and it’s kind of a blank canvas for other flavors. Try it with the cream cheese frosting recipe in that link.
Why should I add zucchini to chocolate cake?
Zucchini adds lots of moisture to cake, tenderizing the crumb and ensuring a softness that you can’t beat. It also adds some fiber, which makes this a healthier cake than some.
Can you taste the zucchini in this healthy zucchini cake recipe?
No! The flavor of zucchini, even if you love it, would seem out of place in a sweet cake. This recipe has no zucchini flavor at all.
Is this a flourless chocolate zucchini cake recipe?
No! This cake is more of a “regular” gluten free cake, made with an all purpose gluten free flour blend. The zucchini doesn’t replace the flour, like the quinoa does in our quinoa chocolate cake.
Can I use almond flour for this zucchini cake recipe?
No, this cake calls for an all purpose gluten free flour blend, which is necessarily rice-based. You can only use almond flour in recipes that are formulated to be made with it, like many of our Paleo recipes.
Is this recipe for chocolate zucchini cake good for making a layer cake?
No, I don’t recommend making this as a layer cake, since it’s so incredibly moist that it doesn’t slice that cleanly. It’s best sliced into rustic squares, as a single layer cake.
Can I use this zucchini chocolate cake recipe to make cupcakes?
I haven’t tried this recipe as cupcakes, and I find that the best cupcakes call for dedicated cupcake recipes. If you decide to try baking the batter in muffin tins, please let us know how it turns out!
Why is my zucchini cake chocolate batter so dry?
Did you measure your ingredients by weight, not volume? It’s not really possible to measure dry ingredients accurately by volume, and you may have overmeasured your gf flour blend. Or, if you used an improperly balanced blend that I recommend against, like King Arthur Flour, your cake won’t turn out as expected.
How to make gluten free chocolate zucchini cake
Gluten Free Chocolate Zucchini Cake
For the cake
- 1 ½ cups all purpose gluten free flour blend (I used Better Batter; please click thru for appropriate blend info)
- ¾ teaspoon xanthan gum omit if your blend already contains it
- ½ cup unsweetened cocoa powder Dutch-processed preferred (if using natural, add 1/8 teaspoon baking soda)
- ½ teaspoon kosher salt
- 1 ½ teaspoons baking powder
- ¾ cup granulated sugar
- 3 tablespoons packed light brown sugar
- 2 ¾ cups shredded zucchini (from about 2 large or 3 medium zucchini) drained of liquid (See Recipe Notes)
- 6 tablespoons neutral oil (vegetable, canola, grapeseed, or peanut oil all work fine)
- 1 teaspoon pure vanilla extract
- 3 eggs at room temperature, beaten
- 9 tablespoons buttermilk at room temperature
- 4 ounces chocolate chunks or chips (optional)
For the fudge frosting
- ⅔ cup evaporated milk
- 1 cup granulated sugar
- 4 ounces bittersweet chocolate melted
- 4 tablespoons unsalted butter melted
Make the cake.
- Preheat your oven to 350°F. Grease and line a 9-inch square baking pan and set it aside.
- In a large bowl, place the flour, xanthan gum, cocoa powder, salt, baking powder and granulated sugar, and whisk to combine well.
- Add the brown sugar and mix to combine, breaking up any lumps in the brown sugar and in the cocoa powder.
- Add the shredded zucchini, and mix to combine until the zucchini is fully coated in the dry ingredients.
- Create a well in the center of the mixture and add the oil, vanilla, eggs, and buttermilk. Mix to combine (the mixture will be thick but soft).
- Add the optional chocolate chips, and mix until they're evenly distributed throughout the cake batter.
- Transfer the batter to the prepared baking pan and spread it into an even layer with a spatula.
- Place the pan in the center of the preheated oven and bake for about 30 minutes.
- The cake is done when the cake springs back when pressed gently in the center with a finger, and a toothpick inserted in the center comes out with a few moist crumbs attached.
- Remove the cake from the oven and allow to cool in the pan for at least 20 minutes before slicing or frosting it.
Make the fudge frosting (optional).
- Place evaporated milk and sugar in a blender and blend for at least 1 minute, or until the sugar is dissolved.
- Add the melted chocolate and butter to the mixture in the blender, and blend for about another 1 minute, or until the mixture thickens to a pudding-like consistency.
- Store the frosting at room temperature in a sealed container until ready to use.
- Spread the fudge frosting on the cooled chocolate zucchini cake, slice into squares with a serrated knife, and serve.
- Alternative serving suggestion: Slice the cooled cake into squares with a serrated knife, and spread frosting on each slice right before serving.