Single Layer Chocolate Cake with Chocolate Ganache

This easy single layer chocolate cake with chocolate ganache is perfect for weeknights, date nights, birthdays, and small dinner parties.  Only one bowl needed and so quick to make – no butter, no eggs, and no mixer required! This one layer cake can be made in an 8-inch round, 9-inch round, 8-inch square cake pan, loaf pan, or cut the recipe in half for a 6-inch round cake pan. All options listed in the recipe notes!

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Note: this recipe was originally published on February 12, 2018. As of March 2022, I’ve updated: (1) some of the photos, (2) the recipe itself to include a few different cake pan sizes you can use and a couple options for the ganache; and (3) a video. This is still one of my favorite recipes of all time and I hope you love it too! It was the first of my single layer cake recipe series. Check out my single layer carrot cake or my single layer lemon cake for other flavor ideas!

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A One Layer Dark Chocolate Cake

True story: I was not planning to share this one layer, eggless, small chocolate cake recipe on here.  In fact, even after Brian and I made it together for my birthday one weekend, and demolished nearly half of it in 24 hours, I still wasn’t planning to share it. 

It’s…simple.  Humble.  Unassuming.  Not really earth shattering – just a good, back-pocket smaller chocolate cake with a tender, light crumb.  And chocolate ganache, because chocolate ganache may sound fancy, but it’s actually the easiest thing to make.

We made this cake because I wanted a simple, unfussy cake for my birthday.  Brian makes me a homemade birthday cake every year and I try not to make it hard for him.  He’s quite good as a baker, actually, but he requires very clear instruction and limited steps, or else he gets nervous.  So I don’t like to give him difficult recipes to contend with in hopes he’ll make me cake more often 😉

The problem is that most chocolate cake recipes make a LOT of cake for two people.  Not a bad problem to have, some might say.  But I saw a challenge: I wanted to create a chocolate cake just as satisfying, just as chocolatey – in smaller portions.

And that was the start of my single layer cake series! It’s an ongoing series of smaller cake recipes that totally deliver on texture and flavor, just in one layer 8 inch or 9 inch proportions.

Recipe Development

This recipe is an adaptation of King Arthur Flour’s “cake pan” cake.  Also called wartime cake or wacky cake, it’s an old cake recipe that relies on the reaction generated by combining baking soda (a base) and vinegar (an acid), rather than traditional butter and eggs, to provide the rise and tender crumb we expect from cakes.

The original recipe is mixed AND baked all in an 8 inch square pan, which was exactly the size I was looking for – enough for two people to have cake for a few days, or for a small dinner party.  I’d made this recipe a couple times in the past, and remembered liking it – and I knew I could make some tweaks to make it even better.

Why You’ll Love This Single Layer Chocolate Cake

Let’s talk about the amazing properties of this single layer chocolate cake, which I made twice in one weekend with no regrets:

• No butter, no eggs.  And you won’t miss them!  The good news is that not only is this cake lighter while still having an amazingly fluffy yet dense texture, it’s also a great option for vegans or for those with egg allergies or intolerances.  Chocolate cake for everyone!
• No mixer required.  Because we’re not creaming butter and sugar and we don’t have to whip in air to create a rise, you don’t need any kind of mixer – just a bowl and a whisk!  Speaking of…
• Only one bowl needed!  Nope, I’m not kidding.  Whisk the dry ingredients together, dump in the wet ones, and stir it all up.  Done.
• Takes 45 minutes to make, including bake time!
• Tastes better the second day.  This is a cake that only gets better with time.  The cake does NOT get dry as long as it’s well-covered, and the chocolate flavor just deepens with a day’s rest.  It works around your schedule.
• Chocolate Ganache.  Everything is better with ganache on top.  And it’s SO EASY.  Can you use a microwave?  You can make ganache.

What size pan can I use?

There are SO many size options for this cake, and I’ve tried them all 🙂 you can use any of the following pan sizes:

• one 8-inch round cake pan: bake for 32-34 minutes
• one 9-inch round cake pan: bake for 28-30 minutes
• one 8-inch square cake pan: bake for 32-34 minutes
• one 9×5 inch or 8.5×4.5 inch loaf pan: bake for 45-50 minutes.
• two 6-inch round cake pans (full recipe): bake for 25-28 minutes
• one 6-inch round cake pan (half recipe): bake for 20-22 minutes

NOTES: The cake will be taller if you use an 8-inch round or square pan and it will take a few minutes longer to bake. I used to prefer using my 9-inch round (the original photos were taken using that pan) but now I like the taller, more generous look of the 8-inch! I also love the loaf and 6-inch options. I have baked the cake as a loaf with mini chocolate chips on top instead of using ganache, and it’s come out wonderfully! See photos below.

Ingredients

You’ll like this simple list of ingredients for a small chocolate cake:

• All-purpose flour
• Natural cocoa powder or Dutch process cocoa powder
• Granulated sugar
• Espresso powder (optional, to bring out chocolate flavor)
• Baking soda
• Salt
• Coffee (or milk, or water)
• Olive oil (or another neutral oil)
• Vanilla extract
• Apple cider vinegar or white vinegar (to react with the baking soda and produce the rise!)
• Dark chocolate (use your favorite bar)
• Heavy cream (or coconut cream for a dairy-free and vegan substitute)

How to Make Chocolate Ganache Cake

For the cake:

1. Preheat your oven to 350 degrees F.  Grease an 8-inch or 9-inch round cake pan, or an 8-inch square pan, and line the bottom of the pan with parchment paper.
2. In a large bowl, whisk together dry ingredients: flour, cocoa powder, sugar, salt, espresso powder, and baking soda. Make sure to whisk vigorously and tamp out any cocoa powder lumps.
3. Pour in the wet ingredients: coffee, olive oil, vanilla, vinegar.  Whisk it all together until a smooth batter is formed.  You’ll notice it might get a little foamy – that’s the baking soda/vinegar reaction happening.  Stop whisking when the mixture is combined and no lumps remain – don’t overmix or the cake will be tough.
4. Pour batter into prepared pan, and bake until cake springs back when touched and a tester inserted in the center comes out clean (time depends on the size of your pan – see recipe card for details).
5. Let cake cool in pan on a rack for 10 minutes, then invert the pan onto the rack to release the cake, remove the parchment from the bottom, and flip back right side up onto a cake plate.  Let cake cool while you prepare the ganache.

For the dark chocolate ganache

If you haven’t made ganache before, here we go:

1. Heat heavy cream in the microwave or on the stove until bubbles appear on the edges, just before boiling. 
2. Pour the hot cream over chopped chocolate or chocolate chips in a bowl. 
3. Wait 30 seconds. 
4. Stir, continuously, until a smooth, shiny chocolate pool of happiness is formed, about 30 more seconds. 
5. DONE.  Pour it warm over the cake OR let it cool to room temperature (this takes 1-2 hours) so you can spread it on.
6. For WHIPPED chocolate ganache frosting: once cooled to room temperature, use a mixer to beat the ganache on medium to high speed until fluffy and lighter in color. It makes a great chocolate frosting!

Storage

Room temperature: Cake without ganache keeps quite well at room temperature, well-wrapped, for up to 5 days.  It doesn’t dry out!  With the ganache, cake should be refrigerated after 24 hours due to the cream. 

Fridge: Cake will keep for up to 5 days, well-wrapped. Either warm leftover slices gently in the microwave or allow to come to room temperature before serving. 

Freezer: Cake can be frozen, well-wrapped, with or without ganache, for up to 3 months. Thaw for 1-2 hours at room temperature or overnight in the fridge before serving.

FAQs and Recipe Tips

More Single Layer Cake Recipes:

• Single Layer Carrot Cake with Cream Cheese Frosting
• Single Layer Lemon Cake with Lemon Cream Cheese Frosting
• Single Layer Guinness Cake with Irish Cream Frosting
• Single Layer Snickerdoodle Cake

Like this recipe for a small one layer chocolate cake?  Please rate it and leave a comment, and sign up for my email list to receive my recipes straight to your inbox every time I post! You can also tag me on Instagram @katiebirdbakes so I can see what you baked. Thank you!