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, or 8-inch square cake pan, or cut the recipe in half for a 6-inch round cake pan.

A slice of single layer chocolate cake with chocolate ganache

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!


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 😉

Single Layer Chocolate Cake with Chocolate Ganache | katiebirdbakes.com

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.

Single Layer Chocolate Cake with Chocolate Ganache | katiebirdbakes.com

Origins of the Recipe

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.

Small chocolate cake coated in shiny chocolate ganache with some pieces sliced on a plate

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 do I need?

You can use an 8-inch round cake pan, 9-inch round cake pan, or 8-inch square cake pan for this single layer chocolate cake. 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 (instructions are in the recipe at the bottom of this post). You can also cut the entire recipe in half and bake it in a 6-inch round cake pan for a truly small chocolate cake for two!

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! See what you think!

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 for 28-32 minutes if using a 9-inch round pan, or 32-34 minutes if using an 8-inch round or square pan, until cake springs back when touched and a tester inserted in the center comes out clean.
  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

Glossy shiny ganache being poured over the cake

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!
Close up bite shot - Single Layer Chocolate Cake with Chocolate Ganache

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

How do I make this one layer chocolate cake gluten-free?

Just use an equal volume of a gluten-free all-purpose flour blend with xanthan gum (I like Bob’s Red Mill Cup for Cup or King Arthur Flour Measure for Measure).

Can I make this cake vegan?

Yes – just use vegan chocolate and use canned coconut cream instead of heavy cream.

Do I need to refrigerate chocolate ganache cake?

This is fine to leave at room temperature for 24 hours, but I would refrigerate it after that for up to 5 days due to the cream in the ganache. The cake itself (unfrosted) is perfectly soft at room temperature for up to a week!

How do I make this into a 6-inch chocolate cake?

Cut the entire recipe in half and bake in a 6-inch round cake pan for 18-21 minutes at 350 degrees F, or until cake springs back when touched and a tester inserted in the center comes out clean. Works like a charm! You could also bake the full recipe in 2 6-inch cake pans and use whipped ganache (instructions above) or a sturdier buttercream frosting to make a layer cake.

Why is there coffee in the batter?

It brings out the deepest chocolate flavor.  There’s something about coffee that brings out the flavor of chocolate.  Ever had a mocha?  You know what I mean.  You can use decaf, regular, whatever you want — and if you don’t like coffee, you can use milk or water too.  No worries.

This chocolate cake for two may be humble, but it is mighty.  It’s just the kind of recipe we all need in our back pocket, whether it be for Valentine’s Day, a loved one’s birthday, or just a Monday.  It’s exactly what I wish for you today.

Overhead shot - Two slices of chocolate ganache cake with forks digging into them on a wooden table

More Single Layer Cake Recipes:

A slice of single layer chocolate cake with chocolate ganache
Print Recipe Pin Recipe
4.99 from 52 votes

Single Layer Chocolate Cake with Chocolate Ganache

Weeknights, date nights, birthdays, parties: this simple and easy single layer chocolate cake with chocolate ganache is perfect for them all. No butter, eggs, or mixer required!
Prep Time15 minutes
Cook Time30 minutes
Total Time45 minutes
Course: Dessert
Cuisine: American
Keyword: cake, chocolate cake
Servings: 8 slices
Author: katiebirdbakes.com

Equipment

  • 1 8 or 9 inch square or round cake pan

Ingredients

For the cake:

  • 1 and 1/2 cups (188g) all-purpose flour
  • 1/4 cup (21g) unsweetened cocoa powder (can use natural or Dutch process)
  • Scant 1 cup (185g) granulated sugar
  • 1/2 teaspoon salt
  • 1/2 teaspoon espresso powder (optional; brings out chocolate flavor)
  • 1 teaspoon baking soda
  • 1 cup (237ml; 227g) brewed coffee (regular or decaf, can be hot or cold)*
  • 1/3 cup (78 ml; 67g) olive oil
  • 1 teaspoon vanilla extract
  • 1 tablespoon apple cider vinegar (or white vinegar)

For the ganache:

  • 1/2 cup (118 ml; 113g) heavy cream
  • 3/4 cup (4 oz; 127g) chopped dark chocolate or semisweet chocolate chips

Instructions

For the cake:

  • Preheat your oven to 350 degrees F.  Grease an 8-inch or 9-inch round cake pan, or an 8-inch square pan.  I also like to line the bottom of the pan with parchment paper, to give extra insurance that the cake will come out cleanly.  Just trace the bottom of the pan on a sheet of parchment paper and cut it out, then place inside the pan.
  • 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.
  • 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.
  • Pour batter into prepared pan, and bake for 28-32 minutes if using a 9-inch round pan, or 32-34 minutes if using an 8-inch round or square pan, until cake springs back when touched and a tester inserted in the center comes out clean.
  • 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 ganache:

  • In a microwave-safe measuring cup or bowl, heat the heavy cream until bubbling but not boiling, about 30-40 seconds in my microwave.  You can also heat it on the stove.
  • While the cream is heating, place the chopped chocolate in a medium bowl.  Pour the hot cream over the chocolate and let stand for about 30 seconds.  Whisk the mixture until a smooth and glossy ganache forms, about 30 seconds. 
  • You can either pour the warm ganache over the cake immediately, or let ganache sit at room temperature for 1-2 hours and then spread it on the cake. It's delicious either way.

Video

Notes

*If you don’t like coffee, you can use water or milk instead.  The coffee brings out the chocolate flavor – you won’t taste it in the cake.
Storage: 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.  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.
To make a 6-inch chocolate cake: Cut all recipe ingredients listed above by half.  Bake cake in a 6-inch round cake pan at 350 degrees for 18-21 minutes, or until cake springs back lightly when touched and a tester inserted in the center comes out clean or with just a couple crumbs.  Pour or spread ganache over and serve!
Recipe adapted from King Arthur Flour’s cake pan cake.
 

If you make this single layer chocolate cake, please leave a STAR RATING and a REVIEW below – it helps others find and enjoy the recipe! You can also tag me on Instagram @katiebirdbakes so I can see what you baked. Thank you!

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!

Leave a Reply

Your email address will not be published. Required fields are marked *

Recipe Rating




This site uses Akismet to reduce spam. Learn how your comment data is processed.

140 Comments

  1. Hi Katie,

    I’ve been making this cake on occasion since I was a kid – I believe that it was invented as a ‘War Cake’ because it didn’t need expensive ingredients like eggs or butter. The one suggestion that I have is to mix the cocoa with only sugar first, which in the food industry is referred to as ‘plating’. This ensures that there are no lumps from the cocoa. Other than that, I really do appreciate your very accurate weights, considering that these days online bakers who attempt to convert from volumetric measurements to grams often get it wrong. And the ganache is a very nice touch – easy cake, easy icing!

  2. 5 stars
    This cake is absolutely delicious!!!! So easy, it takes like a devils food cake but yet it’s super light. The chocolate ganache is amazing too, followed the directions and did not over mix. I made this cake the night before to take it to a friends birthday and everyone just loved it-definitely will be making this again!!!

  3. 5 stars
    Ditto Jill’s accolades! Hurriedly and easily made this cake for a dear friend’s milestone bday. (store bought just wouldn’t have been appropriate) All of us chocoholics, including Birthday Girl, absolutely indulged ourselves! HUGE THANKS for sharing this decadent treat!

  4. 5 stars
    This cake is perfect! My 11 year old (with minimal baking experience) made this all on her own and it turned out perfectly.

  5. 5 stars
    Oh my goodness! Chocolate goodness!! Who knew it’s so easy to make a great chocolate cake with no eggs and no butter? I didn’t! I was a bit skeptical, him, how will this REALLY turn out? Let’s just say this will be my go to recipe for chocolate cake. Moist, flavorful, so chocolatey…and it’s true, it does not dry out. As for the ganache, it’s sooooo good. What else do you need. Just a glass of milk! I consider myself a good baker and I love trying new recipes so Ohmygosh Katie!! Thank you for sharing this recipe, it’s a keeper. P.S. I love how you give a backstory with your recipes, I can so relate!

  6. 5 stars
    Such a rich, flavorful cake! I was planning to make the Guinness Irish cream cake since this weekend is March 17. However, I did not have Guinness nor Irish cream, and really wanted chocolate cake. This is the best and easiest from scratch cake! I will make it again for sure (and will also be more prepared for future Irish holidays). Note: I love coffee. My spouse loves chocolate and does not like coffee. The coffee in this recipe is undetectable.

  7. 5 stars
    I made this for a spontaneous party this week and it was amazing! I baked it the night before and decorated the day of with a spice buttercream. I will definitely be making this again, so easy and quick.

  8. 5 stars
    Wow! This is REALLY a great cake. I have made other “vinegar” cakes, but this beats them all. Absolutely perfect. And SO very easy. I like these small cakes for ease and because there is only my husband and me in the house.

    My other saved recipes for chocolate vinegar cake are officially deleted from my hard drive!

    Thanks, Katie!

  9. 5 stars
    Quick easy for last minute dinner guests I used a mocha buttercream frosting to complement the chocolate it’s out of this world !!!

  10. Ive now made this cake about 20 times. Its perfect and delicious EVERY itmr. Q: my grandson wants for his bday, but w/nuts IN the cake (not just on top). What amt is ok…do i need to change cook time? Tks.

    1. Hi Kay – answered via email but in case anyone else would like to know, yes I think 1/2 cup chopped nuts would work and you do not need to change the baking time! enjoy!

  11. Hey Katie!

    I came across your recipe and thinking about making this soon! I’m going to be using an 8 inch pan. I’m thinking about making some extra chocolate ganache and putting it on top of the cake as well as cutting the cake in half and putting some ganache in the middle too since my husband is a chocolate addict! Do you think that would turn out fine?

  12. 5 stars
    This has become our go-to Chocolate Cake! We make this for every special occasion, but it comes together so easily that we make it even when there isn’t one. Also love that the cake itself is dairy-free, makes it easy to accommodate everyone’s needs. I’ve used both coffee and plant-based milk for the liquid and it’s always been successful. Thank you for such a classic recipe!