Moist Chocolate Coffee Cake with Chocolate Buttercream Frosting

If you love rich chocolate cake, this easy Chocolate Coffee Cake is one recipe you’ll want to make again and again. The cake is wonderfully soft and moist, with a deep chocolate flavor enhanced by a little instant coffee. Don’t worry—the coffee doesn’t overpower the cake. Instead, it helps bring out the richness of the cocoa and chocolate.

The cake is sliced into two layers and filled with a creamy homemade chocolate buttercream frosting made with cocoa, coffee and melted dark chocolate. You can also brush the cake layers with a little sugar syrup or milk to make them even softer.

 

It’s a simple but impressive dessert that’s perfect for birthdays, family gatherings, celebrations or whenever you’re craving a really good homemade chocolate cake.

Ingredients

For the Chocolate Cake

• 120 ml (½ cup) warm milk
• 25 g (3½ tablespoons) cocoa powder
• 1 tablespoon instant coffee
• 200 g softened butter
• 200 g (1 cup) sugar
• 3 large eggs
• 200 g (1⅓ cups) plain or all-purpose flour
• 1¼ teaspoons (6 g) baking powder
• ¼ teaspoon baking soda

 

For the Chocolate Buttercream Frosting

• 1 tablespoon cocoa powder
• 1 teaspoon instant coffee
• 2 tablespoons warm water
• 120 g (½ cup) softened butter
• 240 g (2 cups) powdered sugar
• 100 g dark chocolate, melted and slightly cooled
• 2–3 tablespoons heavy cream, optional

 

For Assembling

• Sugar syrup, optional
• Milk, optional alternative to sugar syrup
• Chocolate sprinkles, for decorating

Equipment

• 20 × 20 cm (8 × 8-inch) baking pan
• Large mixing bowl
• Small mixing bowl
• Electric hand mixer or stand mixer
• Whisk or spatula
• Serrated knife for cutting the cake
• Cooling rack

 

How to Make Chocolate Coffee Cake

Step 1: Prepare the Cocoa and Coffee Mixture

Pour the warm milk into a small bowl.

Add the cocoa powder and instant coffee. Stir thoroughly until the cocoa and coffee have dissolved and you have a smooth chocolate mixture.

Set it aside while you prepare the rest of the cake batter.

This simple mixture gives the finished cake a richer chocolate flavor, while the coffee helps intensify the cocoa.

 

Step 2: Cream the Butter and Sugar

Place the softened butter and sugar in a large mixing bowl.

Using an electric mixer, whisk them together for about 2–3 minutes, or until the mixture becomes lighter, creamy and fluffy.

For the best results, make sure your butter is properly softened before you begin. It should be soft enough to mix easily but not melted.

 

Step 3: Add the Eggs

Add the 3 eggs to the butter mixture.

Whisk for approximately 2 minutes, until the eggs are well incorporated and the mixture looks smooth and creamy.

Room-temperature eggs work particularly well because they combine more easily with the butter.

 

Step 4: Add the Dry Ingredients

In a separate bowl, combine the flour, baking powder and baking soda.

Gradually add the dry ingredients to the butter and egg mixture.

Mix gently until everything is just combined. Avoid overmixing once the flour has been added, as this can affect the soft texture of the finished cake.

 

Step 5: Add the Chocolate Coffee Mixture

Pour the prepared cocoa, coffee and milk mixture into the cake batter.

Fold it in gently until the batter becomes evenly chocolate-colored.

Whisk for about 15 seconds if needed, then give the batter one final gentle mix with a spatula to make sure there are no unmixed ingredients at the bottom of the bowl.

 

Step 6: Prepare the Baking Pan

Preheat your oven to 170°C (350°F).

Prepare a 20 × 20 cm (8 × 8-inch) baking pan by lightly greasing it and lining it with baking paper if desired.

Pour the chocolate cake batter into the pan and spread it evenly.

 

Step 7: Bake the Cake

Bake in the preheated oven for approximately 30–35 minutes.

Check the center of the cake with a toothpick. If it comes out clean or with a few moist crumbs attached, the cake is ready.

Be careful not to overbake it, as this can make a chocolate cake dry.

Remove the cake from the oven and allow it to cool completely before adding the frosting.

 

How to Make Chocolate Buttercream Frosting

Step 1: Make the Cocoa Coffee Paste

Add 1 tablespoon cocoa powder and 1 teaspoon instant coffee to a small bowl.

Pour in 2 tablespoons of warm water and mix until you have a smooth paste.

Set it aside.

 

Step 2: Whip the Butter

Place 120 g of softened butter in a mixing bowl.

Whisk with an electric mixer for about 1 minute, until the butter becomes smooth and creamy.

Step 3: Add the Powdered Sugar

Add approximately half of the powdered sugar to the butter.

Mix briefly on low speed first so the powdered sugar doesn’t fly out of the bowl. Then whisk for another 1–2 minutes.

Add the remaining powdered sugar and repeat the process.

Continue mixing until the buttercream becomes smooth and fluffy.

 

Step 4: Add the Dark Chocolate

Melt 100 g of dark chocolate and allow it to cool slightly.

The chocolate should still be fluid but shouldn’t be hot when added to the buttercream.

Pour the melted chocolate into the frosting and whisk for 1–2 minutes.

 

Step 5: Add the Cocoa Coffee Paste

Add the prepared cocoa and coffee paste.

Whisk again for another 1–2 minutes, until the frosting has an even color and rich chocolate consistency.

Step 6: Adjust the Consistency

If the frosting seems too thick, add 2–3 tablespoons of heavy cream.

Add it gradually while whisking until you reach a smooth and easily spreadable consistency.

The heavy cream is optional, so you can leave it out if you’re already happy with the texture.

Keep the frosting chilled while waiting for the cake to cool completely.

 

How to Assemble the Cake

Once the cake has completely cooled, carefully remove it from the pan.

Using a long serrated knife, slice the cake horizontally through the middle to create 2 even layers.

Place the bottom layer on your serving plate.

For an extra-moist cake, lightly brush or drizzle the surface with a little sugar syrup. If you don’t want to use sugar syrup, a small amount of milk can be used instead.

Don’t soak the cake excessively—you only need enough to add a little extra moisture.

Spread approximately half of the chocolate buttercream evenly over the first cake layer.

Carefully place the second cake layer on top.

If desired, lightly brush the top layer with a little more sugar syrup or milk.

Spread the remaining chocolate frosting generously over the top of the cake.

Finish with chocolate sprinkles for a simple and attractive decoration.

 

Easy Homemade Sugar Syrup

If you’d like to use sugar syrup between the cake layers, you can easily prepare a small amount at home.

Combine equal amounts of sugar and water in a small saucepan. For example, use ¼ cup sugar and ¼ cup water.

Heat gently while stirring until the sugar completely dissolves. Allow the syrup to cool before brushing it onto the cake.

You don’t need to use all of it. Add only enough to lightly moisten each cake layer.

 

Tips for the Best Chocolate Cake

Use softened butter: Both the cake and buttercream work best when the butter is soft but not melted.

Don’t skip the coffee: Even if you’re not a big coffee drinker, the small amount used here helps deepen the chocolate flavor.

Avoid overmixing: Once you’ve added the flour, mix only until the ingredients are combined.

Don’t overbake: Start checking the cake around the 30-minute mark. Overbaking is one of the most common reasons homemade chocolate cake becomes dry.

Cool the cake completely: Never spread buttercream over a warm cake. The heat can melt the frosting and cause the layers to slide.

Let melted chocolate cool slightly: Hot melted chocolate can soften or melt the butter in your frosting.

 

How to Serve

For neat slices, allow the assembled cake to chill briefly before cutting.

Serve it on its own or pair it with fresh berries, whipped cream, vanilla ice cream or a hot cup of coffee.

The combination of moist chocolate cake and creamy dark chocolate frosting makes it rich enough for special occasions while still being easy enough for everyday baking.

 

How to Store

Keep the finished cake covered or in an airtight container.

It can be stored at room temperature for a short period if your kitchen is cool, but because of the buttercream, refrigeration is a better choice for longer storage.

Store it in the refrigerator for about 3–4 days.

For the best texture and flavor, take individual slices out of the refrigerator about 20–30 minutes before serving. This allows the buttercream to soften and the cake to regain its tender texture.

 

Final Thoughts

This Chocolate Coffee Cake is everything a homemade chocolate dessert should be—soft, moist, rich and covered with plenty of creamy chocolate buttercream.

The cocoa gives it classic chocolate flavor, the coffee makes that flavor even deeper, and the melted dark chocolate turns the frosting into something especially rich and indulgent.

Add a little sugar syrup between the layers and finish with chocolate sprinkles, and you’ll have a beautiful homemade cake that’s ready to share with family and friends.

Enjoy!