When it comes to show-stopping desserts, nothing quite compares to a beautifully made layer cake. There’s something timeless and celebratory about slicing into tall, frosted layers and revealing rich fillings inside. This Mocha Layer Cake with Chocolate-Rum Cream Filling is exactly that kind of dessert—the kind that commands attention on a dessert table and leaves a lasting impression long after the last crumb is gone.

A Cake Worth the Occasion

This Mocha Layer Cake is perfect for special moments. Think birthdays, holidays, dinner parties, anniversaries, or any time you want to truly impress. It’s elegant enough for formal celebrations, yet comforting enough to enjoy with a cup of coffee and good company. Because the flavors are mature and well-rounded, it’s especially popular with adults who appreciate desserts that aren’t overly sweet.

Ingredients

For the Mocha Cake Layers:

2 cups (250g) all-purpose flour, spooned and leveled
1 ¾ cups (350g) granulated sugar
¾ cup (75g) unsweetened natural cocoa powder (not Dutch-process)
2 teaspoons baking soda
1 teaspoon baking powder
1 teaspoon fine sea salt
2 large eggs, room temperature
1 cup (240ml) buttermilk, room temperature
½ cup (120ml) vegetable or canola oil
2 teaspoons pure vanilla extract
1 cup (240ml) hot, strongly brewed coffee or espresso

For the Chocolate-Rum Cream Filling:

1 ¼ cups (300ml) whole milk
4 large egg yolks
½ cup (100g) granulated sugar
3 tablespoons (15g) cornstarch
¼ teaspoon salt
4 ounces (115g) high-quality semi-sweet chocolate, finely chopped
2 tablespoons (28g) unsalted butter, cubed
1 ½ teaspoons dark rum (or 1 teaspoon rum extract)
1 teaspoon vanilla extract

For the Mocha Buttercream:

1 ½ cups (340g) unsalted butter, softened to room temperature
5 cups (600g) confectioners’ sugar, sifted
⅓ cup (35g) unsweetened cocoa powder, sifted
¼ cup (60ml) strongly brewed coffee or espresso, cooled
2 teaspoons vanilla extract
Pinch of salt

For Garnish (Optional):

Chocolate-covered espresso beans
Chocolate shavings or curls
A light dusting of cocoa powder

Instructions

Part 1: Bake the Cake Layers

Preheat and Prep: Preheat your oven to 350°F (175°C). Grease and line the bottoms of three 8-inch round cake pans with parchment paper. Lightly grease the parchment.

Combine Dry Ingredients: In the bowl of a stand mixer fitted with the paddle attachment (or a large bowl with a hand mixer), sift together the flour, sugar, cocoa powder, baking soda, baking powder, and salt. Mix on low for 30 seconds to combine.

Add Wet Ingredients: In a separate medium bowl or large measuring cup, whisk together the eggs, buttermilk, oil, and vanilla until smooth. With the mixer on low speed, slowly pour the wet ingredients into the dry. Mix just until combined—the batter will be thick.

Incorporate Coffee: Carefully pour in the hot coffee. The batter will be very thin; this is correct. Mix on low until just combined, scraping the bottom and sides of the bowl as needed.

Bake: Divide the batter evenly among the prepared pans. Bake for 22-26 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs.

Cool: Let the cakes cool in their pans on a wire rack for 15 minutes. Then, carefully run a knife around the edges and invert them onto the racks to cool completely. Tip: Wrap cooled layers tightly in plastic wrap and freeze for 30 minutes for easier, crumb-free frosting.

Part 2: Make the Chocolate-Rum Filling

Heat Milk: In a medium saucepan, heat the milk over medium heat until it just begins to steam. Do not boil.

Whisk Egg Mixture: In a separate bowl, vigorously whisk the egg yolks, sugar, cornstarch, and salt until thick and pale yellow.

Temper: While whisking constantly, slowly drizzle about half of the hot milk into the egg yolk mixture to temper it. Then, pour the entire egg-milk mixture back into the saucepan with the remaining milk.

Cook to Thicken: Cook over medium heat, whisking constantly, until the mixture becomes very thick and bubbles break the surface, about 2-3 minutes. Cook for 1 full additional minute to cook out the cornstarch taste.

Finish: Remove from heat. Immediately whisk in the chopped chocolate, butter, rum, and vanilla until completely smooth and glossy.

Chill: Press plastic wrap directly onto the surface of the pastry cream to prevent a skin from forming. Refrigerate for at least 2 hours, or until completely cold and set.

Part 3: Prepare the Mocha Buttercream

Beat Butter: In the bowl of a stand mixer fitted with the paddle attachment, beat the softened butter on medium-high speed until completely smooth and creamy, about 3 minutes.

Add Dry Ingredients: With the mixer on low, gradually add the sifted confectioners’ sugar and cocoa powder. Mix until incorporated.

Finish with Liquids: Add the cooled coffee, vanilla, and salt. Beat on medium-high speed for 3-4 minutes, scraping down the bowl as needed, until the frosting is very light, fluffy, and spreadable. If it’s too thick, add a teaspoon of milk or coffee. If too thin, add a bit more sugar.

Part 4: Assemble the Cake

Level Layers: If your cake layers have domed tops, use a long serrated knife to carefully slice them off to create flat, even surfaces.

First Layer: Place one cake layer on your serving plate or cake stand. Spread half of the chilled chocolate-rum filling evenly over the top, leaving a small border.

Second Layer: Gently place the second cake layer on top. Spread with the remaining filling.

Third Layer: Top with the final cake layer.

Crumb Coat: Apply a thin layer of mocha buttercream over the entire cake to trap crumbs. Refrigerate for 20 minutes to set.

Final Frost: Frost the top and sides of the cake with the remaining buttercream using an offset spatula. Create swirls or smooth sides as desired.

Garnish: Decorate with chocolate shavings and espresso beans. For best texture and flavor, let the cake sit at room temperature for about 30 minutes before slicing.

Another reason this cake shines is its make-ahead flexibility. You can prepare the cake layers, filling, and frosting in advance, then assemble everything when you’re ready. This makes it an excellent choice for entertaining, since you won’t be scrambling in the kitchen at the last minute.

Flavor Breakdown

What makes this cake so special is the thoughtful layering of flavors:

• Chocolate + Coffee: Coffee doesn’t just add flavor—it intensifies the chocolate, making it richer and more complex.
• Rum Accent: The small amount of rum in the pastry cream adds warmth and sophistication without overpowering the chocolate.
• Creamy vs. Fluffy: The contrast between the smooth filling and the light buttercream keeps every bite interesting.

Each forkful delivers moisture, richness, and balance. Nothing feels heavy or one-note, which is exactly what you want from a celebration cake.

Tips for Success

Before you dive into the recipe, here are a few helpful tips to ensure bakery-quality results:

• Use quality ingredients. Since this cake relies heavily on chocolate and coffee, choose the best cocoa powder, chocolate, and espresso you can.
• Measure accurately. Baking is precise, especially with cakes. Spoon and level your flour, and don’t eyeball ingredients.
• Don’t rush cooling. Fully cooled cake layers are essential for clean assembly and smooth frosting.
• Chill the filling well. A properly chilled pastry cream will hold its shape and make assembly much easier.
• Take your time. This cake rewards patience. Enjoy the process as much as the final result.

Now that you know what makes this cake so special, let’s get into the full recipe. The recipe below is presented exactly as written and has not been changed.

Mocha Layer Cake with Chocolate-Rum Cream Filling

Active Time: 45 minutes | Total Time: 3 hours (includes cooling & chilling) | Difficulty: Intermediate | Yield: 12 generous slices

There’s no celebration quite complete without a spectacular layer cake. This Mocha Layer Cake is a coffee and chocolate lover’s dream come true. Featuring supremely moist espresso-infused cake layers, a luxuriously smooth chocolate-rum pastry cream, and a rich mocha buttercream, every bite is a perfect balance of bitter, sweet, and deeply flavorful. It’s a project worth undertaking for a special birthday, holiday, or any time you want to impress.

Why You’ll Love This Recipe:

Deep, Complex Flavor: The combination of high-quality cocoa, fresh brewed coffee, and a hint of rum elevates basic chocolate cake to a sophisticated dessert.

Textural Heaven: Enjoy the contrast of tender cake, creamy filling, and fluffy frosting.

Make-Ahead Friendly: Each component can be prepared a day in advance, making assembly a breeze.

Nutrition Information (Per Serving, 1/12 of cake)

Calories: 785 | Total Fat: 40g | Saturated Fat: 21g | Trans Fat: 1g | Cholesterol: 155mg | Sodium: 490mg | Total Carbohydrates: 105g | Dietary Fiber: 3g | Sugars: 85g | Protein: 8g

Final Thoughts

This Mocha Layer Cake with Chocolate-Rum Cream Filling is more than just a dessert—it’s an experience. From the aroma of brewed coffee in the batter to the final decorative touches on top, every step feels intentional and rewarding. If you’re looking for a cake that delivers bold flavor, elegant presentation, and unforgettable results, this is the one to bake.

Serve it with coffee, espresso, or even a glass of milk, and watch it disappear slice by slice. Once you make it, this cake is sure to become a favorite for celebrations and special occasions.