Mini Chocolate Cake

This Mini Chocolate Cake is a rich, moist 6-inch chocolate cake topped with fluffy chocolate buttercream and plenty of sprinkles. It makes about four servings, making it perfect for a small birthday celebration, date night, or anytime you’re craving chocolate cake without needing a full-size layer cake.

 

I originally developed this chocolate cake batter for my small batch chocolate cupcakes, but I wanted to see if I could turn that same easy batter into one small cake. After testing it in a 6-inch cake pan, I loved how it baked up—thick enough to feel like a real celebration cake but small enough that you’re not left with cake for days.

I use oil instead of butter in the cake batter because it keeps the chocolate cake especially soft and moist, even after it’s been refrigerated. I love using canola, vegetable or avocado oil, but any neutral-tasting oil will work.

And the frosting? Oh my. Don’t skip that. Not that you would. It’s so fluffy, and rich in chocolate flavor. It’s a half batch of my chocolate buttercream frosting and is the perfect amount to frost the sides and top of the cake.

Why This Recipe Works

• It makes just four servings. This one-layer 6-inch chocolate cake gives you a real homemade cake without the leftovers of a full-size layer cake.
• Oil keeps the cake moist. I use a neutral-tasting oil instead of butter, which gives the cake a soft, moist crumb and helps it stay that way even after refrigeration.
• Buttermilk makes it extra tender. The acidity in the buttermilk reacts with the baking soda while also helping create a soft, tender cake.
• You don’t need a mixer for the cake batter. The wet and dry ingredients are simply whisked together, making this a quick batter to mix up.
• The frosting is scaled for one small cake. There’s enough chocolate buttercream to generously frost and decorate the top without making a full batch of frosting.

Ingredients

For the Chocolate Cake

• All-purpose flour: For the most accurate results, weigh your flour with a kitchen scale or spoon it into the measuring cup and level it off.
• Unsweetened cocoa powder: Natural unsweetened cocoa powder or Dutch process works well here.
• Baking powder
• Baking soda
• Salt
• Egg: Bring the egg to room temperature so it combines easily with the other ingredients.
• Granulated sugar
• Vanilla extract
• Neutral-tasting oil: I used avocado oil, but canola or vegetable oil will also work.
• Buttermilk: Buttermilk helps keep the chocolate cake tender and moist. Bring it to room temperature before mixing. If you don’t have any you can make your own. ReadHow To Make Homemade Buttermilk

For the Chocolate Buttercream

• Unsalted butter: Make sure the butter is softened before you begin so the frosting whips up smooth and fluffy.
• Powdered sugar: If yours is particularly lumpy, sift it before adding it to the butter. Run out? Read How To Make Powdered Sugar.
• Heavy cream: Add a little more as needed if your frosting is too thick for piping.
• Vanilla extract
• Unsweetened cocoa powder or Dutch-process cocoa powder: Either will work in the frosting. Dutch-process cocoa will give you a darker chocolate color and flavor.
• Sprinkles: Optional, but an easy way to finish the cake. Chocolate or rainbow work.

How to Make a Mini Chocolate Cake

1. Prepare the cake pan.

Preheat the oven to 350°F (180°C). Grease a 6-inch round cake pan and line the bottom with parchment paper.

The parchment makes it much easier to release the cake cleanly from the pan once it’s baked.

2. Combine the dry ingredients.

In a medium mixing bowl, whisk together the flour, cocoa powder, baking powder, baking soda, and salt.

Whisking everything together before adding it to the wet ingredients helps distribute the leavening evenly throughout the batter.

3. Combine the wet ingredients.

In a separate mixing bowl, whisk together the egg, granulated sugar, vanilla, oil, and buttermilk until smooth and well combined.

Room-temperature ingredients combine more easily, so you won’t need to overmix the batter later.

4. Make the chocolate cake batter.

Add the dry ingredients to the wet ingredients and stir just until combined.

Once you no longer see streaks of dry flour, stop mixing. Overmixing develops more gluten and can make your chocolate cake tougher instead of soft and tender.

5. Bake.

Pour the batter into the prepared 6-inch cake pan and spread it into an even layer.

Bake for 25–28 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs attached.

Let the cake cool in the pan for about 5 minutes, then carefully turn it out onto a wire rack. Remove the parchment and let the cake cool completely before frosting.

Don’t try to frost a warm cake. Even slightly warm cake can melt your buttercream and cause it to slide right off.

Make the Chocolate Buttercream

1. Whip the butter.

In the bowl of a stand mixer fitted with the paddle attachment, beat the softened butter on medium-high speed for about 1 minute, until smooth and fluffy.

Starting with properly softened butter is important. Butter that’s still cold can leave you with lumps, while overly warm butter can make the frosting too soft.

2. Add the powdered sugar.

Turn the mixer to low and gradually add the powdered sugar.

Once incorporated, increase the mixer to medium-high speed and beat for 1–2 minutes until fluffy.

Adding the sugar gradually keeps it from flying out of your mixer and also makes it easier to create a smooth buttercream.

3. Add the vanilla and cream.

With the mixer on low, add the vanilla and heavy cream. Mix until combined.

If the frosting seems too thick later, you can add another small splash of cream.

4. Add the cocoa powder.

Add the cocoa powder with the mixer running on low. Starting slowly is important unless you want a cloud of cocoa powder covering your kitchen!

Once incorporated, increase the mixer to medium-high and beat until the buttercream is light and fluffy. Stop and scrape down the bowl as needed so everything mixes evenly.

5. Decorate.

Once the cake is completely cool, spread the frosting on the top and sides of the cake with an offset spatula.

Finish with sprinkles, if desired.

Recipe Tips

• Measure your flour carefully. Too much flour can make a small cake dry quickly because there’s less batter to begin with. I recommend weighing the flour for the most accurate results.
• Don’t overmix the batter. Once the dry ingredients are added, stir only until they’re incorporated. Overmixing can make the cake tougher instead of soft and tender.
• Don’t overbake the cake. Start checking around 25 minutes. Remove the cake when a toothpick comes out clean or with a few moist crumbs rather than waiting until the cake looks dry.
• Cool the cake completely before decorating. If there’s any warmth left in the cake, the butter in your chocolate frosting can soften or melt.
• Adjust your frosting consistency as needed. If the buttercream is too stiff to pipe, add heavy cream a teaspoon at a time. If it’s too soft, add a little more powdered sugar.

Recipe FAQs

Storage and Freezing

The frosted Mini Chocolate Cake can be stored covered at room temperature for up to 1 day if your kitchen is cool. For longer storage, keep it covered in the refrigerator for up to 4 days. Let refrigerated slices sit at room temperature for about 20–30 minutes before serving for the best texture.

To freeze the unfrosted cake, let it cool completely, then wrap it tightly in plastic wrap followed by aluminum foil or place it in a freezer-safe bag. Label it with the recipe name and date and freeze for up to 3 months.

You can also freeze individual frosted slices. Freeze them briefly on a baking sheet until the frosting is firm, then wrap them well and transfer them to a freezer-safe container.

Thaw the cake overnight in the refrigerator or for a few hours at room temperature. Since this is a cake rather than cookie dough, there’s no need to bake it again from frozen.

More Recipes to Try

If you’re craving more small batch chocolate desserts, try my Brownies for Two, Mini Cookie Skillet, Small Batch Chocolate Chip Cookie Bars, or Small Batch Vanilla Cupcakes next.

They’re perfect when you want something homemade and chocolatey without making a full-size dessert.