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(This is a recipe for two 3/4″ cake layers. Click here for a chocolate frosting recipe and here for a complete mocha cake recipe, as pictured.)
I’ve posted a chocolate cake recipe before which I loved, but it was very dense and fudgy and not a normal cake texture. Also, it contained cauliflower, which I didn’t expect everyone to be excited about. This chocolate layer cake contains no funky ingredients, unless you consider zucchini strange. I don’t; bakers have been using zucchini to add moistness to baked goods for ages. Not only does this cake contain no strange vegetables; but it also contains no almond flour, which is both expensive and calorie-dense.
This is the closest I have come to a normal chocolate cake, in both texture and flavor (although it’s still more dense than a regular cake). In fact, when I used it in this mocha cake recipe for my birthday and served it with vanilla ice cream, I couldn’t have told the difference between this cake and a regular one made with white flour and sugar.
If you have cake, you need frosting. Try this basic chocolate frosting to top it with; and for a mocha mousse filling to put between the layers, check out this mocha cake recipe.
A fantastic addition to this cake would be some sugar-free chocolate chips sprinkled on top of the batter before baking. Add some pecans and caramel sauce and you would have something like a turtle cake. Hmm…I’ll have to work on that…
You can snag my “official” pin for this recipe here.
You can find a cleaned-up version of this recipe in my cookbook, Necessary Food.

- 2 cups frozen grated zucchini, thawed, juice and all (measure before freezing; see note below if using fresh zucchini)
- 3 eggs
- ¼ cup refined coconut oil or butter, melted/softened
- ¼ cup olive oil
- 1 tsp. vanilla extract
- ½ cup oat fiber (use gluten free if necessary)
- ½ cup cocoa powder
- ⅔ cup oat flour (oats ground finely in a blender/coffee grinder; use gluten free if necessary)
- ⅓ cup ground golden flax
- 2 tsp. baking powder
- ½ tsp. baking soda
- 1 tsp. salt
- ¼ tsp. + 2 doonks THM Pure Stevia Extract Powder (a doonk is 1/32 tsp.)
- 4 packets Truvia (3 tsp. Truvia; you could also use 2 tsp. THM Super Sweet Blend), or more to taste since I tend to undersweeten
- Mix all the wet ingredients together well. Whisk the dry ingredients together, add to the wet ingredients, and mix until well combined. Divide the batter into two well-greased 9-inch cake pans and smooth out with a spatula. Bake at 350 degrees F for 15 minutes or until a toothpick comes out cleanly. Let the cakes sit in the pans for 10 minutes, then cut around the edges with a knife and carefully invert them (use your hand to support the cake from underneath and gently tap on the pan to get the cake to loosen if it sticks) onto a towel-covered wire rack to cool. Refrigerate the cake layers until completely chilled through, then frost with your choice of frosting.
The carbs from the oat flour come out to 4.4 net carbs/serving if you cut the cake into 10 slices (those are big slices). This is well within Trim Healthy Mama S guidelines. To avoid using oat flour, use my Baking Mix variation.
To use Briana's Baking Mix in this recipe, substitute 1½ cups of Briana's Baking Mix for the oat fiber, oat flour, and flaxmeal called for in the recipe. Add ¼ cup of egg whites.
Briana’s Baking Mix
Use this sweetener conversion chart for reference if you’re using sweeteners other than what I have listed in the recipe.
Suggested Products:
- FYI: Oat fiber is not the same as oat flour (which is just ground up oats; you can do this in your blender/coffee grinder). You can buy oat fiber here. You can buy a gluten free brand from the Trim Healthy Mama online store.
- I use Hershey’s brand cocoa powder.
- THM Pure Stevia Extract Powder does a great job of sweetening, but in chocolate recipes I like to combine it with Truvia for a more balanced flavor. You can buy the stevia (as well as THM Super Sweet Blend) from the Trim Healthy Mama online store.
I have to say this is the best THM chocolate cake! It is light and airy with no detection of the secret ingredient, zucchini. Last year, I made this recipe into cupcakes at a birthday party for my diabetic sibling. I have tried other chocolate cake recipes since then and nothing compares. I’m glad I found this recipe…again!
This sounds yummy. I have never frozen zucchini before. Do you blanch it or steam it first? Not sure how to blanch grated zucchini 🙂
Nope, we just grate and freeze it as-is!
I am sooooo excited to find this! I’ve been on the hunt for an S cake that doesn’t have almonds or coconut since I’m allergic. I can’t edit to try it!!!!!
Hey Briana!
I’d like to make this today for a birthday, but was wondering if you had an idea of how much THM baking blend to use? Or if that would work? I know your baking blend is a bit dryer then THM baking blend, so should I add a bit more to it?
Yes, general rule of thumb is to use 1 cup of THM Baking Blend for every 3/4 cup of my baking mix, then adjust from there as necessary. 🙂
Thank you!!!
Would it be possible to substitute coconut flour for the oat fiber. I just wondered because it seems that they are both very absorbent.
The textures are pretty different (coconut flour can be quite gritty and require more eggs/conditioners), so I don’t recommend a straight substitution.
It’s simply beautiful Briana, can’t wait to make this for my birthday (Dec 25)…maybe I’ll have to bake a practice cake in the meantime! 😉 birthday blessings!
Happy Birthday in advance!
This is a wonderful recipe! I made it as cake the fist time and it was wonderful. I also made it as cupcakes for a healthy alternative for a wedding and it was WOW! The only downfall was that they were better than the cupcakes made by a professional baker with all the “bad stuff” in them (white flour, sugar etc) lol. I’m about to make it a third time as a cake again 🙂 I love many of your recipes (haven’t tried them all yet ;)), Briana, and have much appreciation of the fact that you write down your ideas in a coherent manner! My family would love it if I took lessons from you – as a young stay-at-home daughter I also love creating recipes and health-ifying them but usually don’t write what I do down lol! Thanks again and keep up the “sweet” work you do!
Aw, thank you so much, Sara! That’s quite the compliment! (And trust me, the most frustrating part about blogging is writing everything down. 😛 I would much prefer not to do so, but people complain if I don’t. Haha)
Wow, this sounds wonderful and healthy,(and pretty) but SO labor intensive and JUST PLAIN HARD to make. I read briefly through the instructions and I don’t even think I would begin to try it. Is there anything simpler that is THM friendly or HOW do people get used to actually CONSTRUCTING something like this? 🙂
I’m afraid I can’t identify – I don’t think it’s hard at all. The cake itself is extremely easy, and even if you do decide to do the extra steps and make the mousse and frosting for a mocha cake, none of the parts are hard. Any full-fledged cake you make with cake, filling, AND frosting, THM or not, is going to be a little involved. For special occasions, it’s worth it. This isn’t the kind of thing I make on a day to day basis. If you want something easy just for grab and go throughout the week, check out my Butterfinger Bar recipe.
Ok. I will look them up too. I guess that is why you have the beautiful food blog and I do not!
So do you cook the zucchini? And it is just grated zucchini, right? I am having a hard time picturing the zucchini and the juice and how to prep the zucchini. I can’t imagine where to get oat fiber. What isle is it in?
I used fresh zucchini that was grated, then frozen. I thawed it out, measured it, and used some of the leftover zucchini juice for the liquid in the recipe. If you decide to use fresh grated zucchini (without freezing first), it might not “decompose” in the recipe quite as much, but it should work fine. If your zucchini doesn’t have enough juice to use for the liquid, use unsweetened almond milk for the liquid called for in the recipe.
Oat fiber is only available on line. There are links below the recipe.
Hi Briana, I am allergie to oats, how can I use the almond flour and the coconut flour, also I don’t like stevia, what can I use for sustitue the sweet,.
Hi! You may be able to substitute almond flour for the oat flour, but I haven’t tried that. As for sweetener, feel free to substitute with any low glycemic sweetener of your choice. This sweetener conversion chart might help: http://www.trimhealthymama.com/main-home/sweetener-conversion-chart/
Briana, I’m allergic to chocolate, but love Lemons & strawberries. Do you think this would work by replacing the chocolate with protein powder. And have you made this with your baking blend or even the THM Baking Blend?. I see this is an older post but i just saw this on the THM facebook post you did. Thanks.a
Wow, that’s unfortunate! I’m not sure about the protein powder thing – texture wise it might work, but I’m not a huge fan of being able to taste protein powder. Feel free to give it a try, though! I don’t have my own baking blend recipe, but no, I haven’t tried this with THM Baking Blend. If you’re looking for a basic white cake recipe, you could use this one here (check the comments for ideas on how to make it a full-size cake): https://www.briana-thomas.com/5-ingredient-white-cake/
My strawberry shortcake recipe might be a good fit as well: https://www.briana-thomas.com/strawberry-shortcake/
can this be baked ina 9*13 would baking time need to be changed?
I don’t see why you couldn’t (although it might be a little thinner). I’m not sure about the baking time as I’ve never tried it. Just do the toothpick test. 🙂