This 6-inch chocolate cake recipe is for a moist single-layer chocolate cake. It is frosted with a smooth chocolate Swiss meringue buttercream frosting.
A small 6-inch chocolate cake like this serves 6-8 slices making it perfect for a small group of people. It has a fluffy chocolate cake base, paired with a luscious and smooth chocolate Swiss meringue buttercream frosting.
Why make a 6-inch cake?
Most cake recipes are made in standard 8-9 inch cake tins and sometimes have multiple cake layers. Most birthday cakes are this size for instance but sometimes making smaller 6-inch cakes are the perfect cake for more intimate occasions.
- Valentine’s day – If you or your partner is a chocolate lover, this small-batch recipe is a wonderful dessert to make.
- Date night – Even if it’s not valentine’s day you can always make this anytime as a special surprise for your loved one.
- Smash cake – If celebrating a child’s first birthday, then making a 6-inch cake is a perfect size for them to wreak havoc on. I’ve got a 6-inch vanilla cake too!
- Other small celebrations – birthdays, anniversaries, or any other celebration you wish to celebrate with a small group of people.
See more small-batch recipes!
Chocolate buttercream is always great but this version uses a Swiss meringue method which makes the frosting smooth, shiny, and most importantly gives a delicious chocolate flavor. It’s much less sweet than American buttercream too and pairs perfectly with the cake.
To make Swiss meringue buttercream, heat egg whites with granulated sugar, and salt until all the sugar has dissolved. Whip the egg whites using a stand mixer until stiff glossy peaks are formed. When the meringue is cooled, add the butter in slowly while continuing to mix. You can use the leftover yolks in these egg yolk cookies.
After the butter has all been incorporated, add the melted chocolate. The end result is a creamy frosting that is extra smooth and not overly sweet.
The actual ingredient amounts for this 6-inch chocolate cake are listed in the recipe card at the bottom of this post. Here is just a rundown of what is used with a little extra information.
- All-purpose flour – AP flour is the base of the dry ingredients in this mini chocolate cake recipe.
- Unsweetened cocoa powder – Cocoa powder gives the cake a chocolate flavor and is a key ingredient in the cake mix. You can use natural cocoa powder or dutch-processed cocoa powder.
- Salt – A small amount is added to the flour mixture. Salt always helps to enhance the flavor.
- Granulated sugar – For sweetness
- Soft brown sugar – The brown sugar sweetens the cake alongside the granulated white sugar and it brings some moisture.
- Vegetable oil – The oil helps make the cake batter rich and smooth and keeps things moist.
- Baking powder and baking powder – The leavening agents to help the cake rise.
- Whole milk – You can use buttermilk if you have it instead of milk and apple cider vinegar.
- Apple cider vinegar (ACV) or white vinegar- Unlike buttermilk, milk and vinegar are ingredients more likely to have at home. If you do have buttermilk, the whole milk + the apple cider vinegar can be substituted for equal parts of buttermilk.
- Vanilla extract – Always an excellent addition to improve the cake taste.
- Egg – One large egg to give some structure.
- Hot coffee or hot water – Hot water is added to some instant coffee or espresso powder. Coffee deepens the chocolate flavor a lot. If you want to omit it, substitute it with plain hot water.
Swiss meringue buttercream
- Egg whites: Egg whites are used with the sugar to form the Swiss meringue base.
- White granulated sugar – Not powdered sugar.
- Room temperature butter: You can use salted butter or unsalted butter. If using salted butter then you can omit the extra salt from the recipe, or leave it in. The extra salt is quite a nice balance with the sweet chocolate.
- Salt: Adding a pinch is the easiest way to deepen the flavor.
- Chocolate: Use high-quality baking chocolate. Do not use chocolate chips or compound chocolate.
- Vanilla – A perfect pairing with chocolate.
There are a few kitchen tools needed to make this small chocolate cake recipe.
- 6-inch round pan – This cake needs to be made in a deep 6-inch round cake pan with a deep rim. It rises into quite a tall cake so you want to give it room to expand.
- Parchment paper – To line the 6-inch pan.
- Mixing bowls – One mixing bowl for the dry ingredients and a large bowl for the wet ingredients.
- Scale – To measure the ingredients. If you choose to use a measuring cup instead, note that the cup sizes given in the recipe card are for US-size cups which are smaller than metric.
- Stand Mixer and/or hand mixer- A stand mixer is best for making meringue buttercream. You’ll need the whisk attachment and a paddle attachment. If you don’t have a stand mixer then you can use a handheld electric mixer and a large mixing bowl but it will take a lot of time to whip the butter into the meringue.
- Thermometer (optional) – This is helpful to measure the temperature of the egg whites for the frosting but it’s not a necessity.
- Offset spatula – To help spread the chocolate frosting evenly on the cake.
- Airtight container – To store the cake afterward.
Preheat the oven to 350°F/ 180°C. Grease and line a 6-inch cake pan.
In a bowl whisk together the flour, cocoa powder, salt, baking powder, and baking soda and set aside.
Measure out the milk and add the apple cider vinegar or lemon juice. Let this sit and curdle for a couple of minutes.
In a separate bowl add the egg, sugars, vanilla, and vegetable oil and whisk together.
Add 1/3 of the dry ingredients at a time to the wet ingredients in the bowl along with 1/3 of the milk mixture and fold it together with a rubber spatula.
Repeat this with the remaining flour and milk.
Pour in the hot coffee and fold it in until everything is well combined, but don’t over-mix it.
Pour the cake batter into the prepared cake pan and bake for approximately 30 minutes until a cake tester inserted into the middle of the cake comes out clean. The bake time will change depending on your oven.
Let the cake cool in the pan for 5 minutes before turning it out onto a wire rack. Let the cake cool completely before frosting.
Melt the chocolate in a bowl in the microwave or over a hot water bath and set it aside to let it cool to room temperature.
In the bowl of your stand mixer add egg whites, sugar, and salt. Bring a pot with 1-inch of water to a simmer and balance the bowl over top.
Whisk constantly until the mixture becomes foamy and all the sugar has dissolved when a little is rubbed between your fingers. If you have a thermometer, the temperature should be around 160°F/71°C.
Place your bowl in your stand mixer fitted with a whisk attachment and begin whisking the meringue on medium speed until the meringue has cooled down completely to room temperature and it’s thick and glossy with stiff peaks.
Begin adding in the butter, a cube at a time, and not adding in the next cube until the previous cube has been completely incorporated. Once the butter is incorporated the meringue can split and look curdled and grainy. This is normal.
Switch the mixer to high speed and keep beating until the meringue comes together and is smooth and thick. If this doesn’t happen even after 15 or more of beating, your butter may be too cold. Place the bowl over a hot water bath for a minute or two to slightly warm the butter. Not too much though! Then beat it until creamy.
Turn off the mixer and pour in the melted chocolate. Turn the mixer high and keep beating until the chocolate is all incorporated and the meringue is fluffy.
Switch to a paddle attachment and beat the Swiss meringue buttercream on medium speed for 5-10 minutes to smooth it out.
Frosting the cake
Scoop the chocolate Swiss meringue buttercream on top of the cooled cake. Use an offset spatula to generously spread it around to coat the top of the cake and the sides.
Serving and storing
Leftover cake can be stored at room temperature in an airtight container for up to 3 days or in the fridge for up to 5 days.
The unfrosted baked cake can also be frozen for up to three months.
Swiss meringue buttercream can be made in advance at can be stored at room temperature for up to 3 days or in the fridge for up to 5 days. It can also be frozen for up to three months. Refrigerated or frozen Swiss meringue buttercream will need to come to room temperature and re-whipped again to make it fluffy.
More cake recipes to try
- Sourdough red velvet cake
- Gluten-free chocolate cake
- Lemon curd cake
- S’mores Baked Alaska
- Double chocolate banana bread
- Raspberry mascarpone cake
- 83g (2/3 cup*) all-purpose flour
- 25g (1/4 cup) cocoa powder
- 1/2 teaspoon baking powder
- 1/4 teaspoon baking soda
- 1/4 teaspoon salt
- 1 large egg
- 66g (1/3 cup) granulated sugar
- 50g (1/4 cup) soft brown sugar
- 45g (3 1/2 Tbsp) vegetable oil
- 1/2 teaspoon vanilla paste or extract
- 1/2 teaspoon Apple cider vinegar (or white vinegar or lemon juice)
- 60g (1/4 cup) milk
- 60g (1/4 cup) hot water
- 1/2 teaspoon instant espresso powder**
Chocolate Swiss meringue buttercream
- 2 large egg whites (60g/2 oz)
- 66g (1/3 cup) granulated sugar
- Pinch of salt
- 170g (3/4 cup) unsalted butter, softened to room temperature.
- 113g (4oz) good quality semi-sweet chocolate
- 1/2 teaspoon vanilla paste or extract
- Preheat the oven to 350°F/ 180°C. Grease and line a 6x3-inch round cake pan.
- In a bowl whisk together the flour, cocoa powder, salt, baking powder, and baking soda and set aside.
- Measure out the milk and add the apple cider vinegar or lemon juice. Let this sit and curdle for a couple of minutes.
- In a separate bowl add the egg, sugars, vanilla, and vegetable oil and whisk together.
- Add ⅓ of the dry ingredients at a time to the egg mixture in the bowl along with ⅓ of the milk and fold it together with a rubber spatula. Repeat this with the remaining flour and milk.
- Dissolve the instant coffee in the hot water. Pour the hot coffee into the batter and fold it until well combined.
- Pour the cake batter into the prepared ban and bake for approximately 30-35 minutes until a cake tester inserted into the middle of the cake comes out clean. The bake time will change depending on your oven.
- Melt the chocolate in a bowl in the microwave or over a hot water bath and set it aside to let it cool to room temperature.
- In the bowl of your stand mixer add egg whites, sugar, and salt. Bring a pot with 1-inch of water to a simmer and balance the bowl over top.
- Whisk constantly until the mixture becomes foamy and all the sugar has dissolved when a little is rubbed between your fingers. If you have a thermometer, the temperature should be around 160F/71C.
- Place your bowl in your stand mixer fitted with a whisk attachment and begin whisking the meringue on medium speed until the meringue has cooled down completely to room temperature and it's thick and glossy with stiff peaks. Touch the sides of the bowl to check. It should be cool to the touch.
- Begin adding in the butter, a cube at a time, and not adding in the next cube until the previous cube has been completely incorporated. Once the butter is incorporated the mixture can split and look curdled and grainy. This is normal.
- Switch the mixer to high speed and keep beating until the mixture comes together and is smooth and thick.
- Troubleshooting- If after 15 minutes the mixture is still curdled, your butter might have been too cold. Place the bowl over a hot water bath for a minute or two to slightly warm the edges of the bowl and melt a tiny bit of the butter. Place it back on the mixer and beat until creamy. In the same regard, if the mixture is too warm and sloppy, and greasy, place the bowl in the fridge for a few minutes then beat again.
- Turn off the mixer and pour in the melted chocolate and vanilla. Turn the mixer high and keep beating until the chocolate is all incorporated and the frosting is fluffy.
- Switch to the paddle attachment and beat on low speed for 5-10 minutes to remove some of the larger air bubbles in the buttercream.
- Scoop the chocolate swiss meringue buttercream on top of the cooled cake. Use an offset spatula to generously spread it around to coat the top of the cake and the sides.
- Store leftover cake in an airtight container at room temperature for up to three days.
*The cup sizes are for US size cups which are smaller than metric. For best results use scales.
** coffee deepens the chocolate flavor. If you want to omit it, just leave it out and add in plain hot water.
Nutrition Information:Yield: 8 Serving Size: 1
Amount Per Serving: Calories: 322Total Fat: 21gSaturated Fat: 10gTrans Fat: 1gUnsaturated Fat: 9gCholesterol: 31mgSodium: 261mgCarbohydrates: 34gFiber: 2gSugar: 23gProtein: 3g
This is an informational estimate only. I am not a certified Dietitian or Nutritionist
Press your finger lightly in the middle of the cake. It should bounce back when pressed. A cake tester or skewer can also be inserted. It will come out clean when the cake is baked.
This cake recipe makes a nice and moist chocolate cake. If your cake is dry it is likely you have over-measured your flour. For best results use scales and measure in grams.
Yes, it can be frozen for up to three months. Wrap it tightly in plastic wrap to avoid freezer burn. Let the cake thaw at room temperature for a few hours, or in the refrigerator overnight.
Yes, white chocolate can be used for a white chocolate version instead. See this Swiss Meringue Buttercream post for more details.
This will make 9-10 chocolate cupcakes. To make a larger batch, check out this chocolate cupcakes with caramel filling post.
The recipe can be doubled and baked in two 6-inch cake pans to make a double-layer chocolate cake.