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
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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!

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140 Comments

  1. 5 stars
    Made this cake exactly as described minus no ganache. It was so simple and delicious. I needed a small single layer cake to make a chocolate cake tiramisu and let me say the chocolate cake was the best part. Will be using this recipe to attempt a chocolate cake tres leche. Perfect size for my hubby and I have to have a little dessert after dinner for the whole week.

  2. 5 stars
    I’ve made wacky cakes in the past but this one tasted SO much better. Does coffee make that much of a difference? Or the olive oil? I didn’t even use espresso powder. Thanks for the tweaks.

    1. Yes! the coffee makes a big flavor difference and so does the olive oil – both for flavor and velvety texture. I also designed the recipe to have a bit less sugar and a bit more salt than most wacky cake recipes, which I think leads to better flavor. highly recommend trying it with the espresso powder too. so glad you enjoyed it!

  3. 5 stars
    I’ve made this cake at least a dozen times following the written recipe and it downright delicious. Be sure to add the coffee and only use heavy cream for the ganache. Decadent so a small wedge will suffice. Freezes well too! Thank you for all your small cake recipes. They are easy and quick to make and bake.

  4. 5 stars
    I’ve made this lovely cake at least 6 times. It’s so delicious and simple to make and the ganache is kind of elegant and wonderful for a dinner party! I usually use raspberries also, but strawberries are good too. Thank you so much for your recipe♡

  5. 5 stars
    This is a wonderful chocolate cake recipe. It was very easy ( I had all the ingredients) to make. I used 2 six inch cake pans. one pan went in the refrigerator and the other we ate right away. I thought the chocolate tasted more rich. I will definitely make this again and again.

  6. 5 stars
    This is now my go-to chocolate cake. It’s perfect every time. The cake itself is not too sweet so the ganache is a must. I serve it with fresh whipped cream.

  7. 5 stars
    This Single Layer Chocolate Cake with Chocolate Ganache looks absolutely indulgent, The simplicity of the one-layer cake makes it perfect for a quick and satisfying chocolate fix. The rich ganache on top adds a luxurious touch and looks so glossy and smooth. I appreciate how straightforward the recipe is, making it accessible for any level of baker. This cake is ideal for a small celebration or just a treat for yourself. Thanks for sharing such a decadent and easy-to-make recipe.

  8. 5 stars
    I’ve made this cake several time now and my husband and I just love it! It’s so simple to make and perfect for satisfying that chocolate craving! I usually add chopped walnuts to the batter and omit the ganache. Instead, I make a quick glaze on the stove top with cocoa powder, sugar, vanilla, milk and a little butter- no measuring, just to taste and consistency. It’s delicious! Thanks for this amazing recipe!

  9. 5 stars
    Katie, this was a wonderful chocolate cake! Loved how moist and tender the crumb was! Will defo be my go-to from now onwards.
    I made these changes to the cake: I used only 150g of sugar (120g white, 30g brown) and for the ganache I used coconut milk in place of the heavy cream. Thank you for sharing your recipe!