I just finished frosting this Guinness Chocolate Cake With Irish Buttercream, and I had to stop and appreciate how amazing my kitchen smells.

The rich aroma of chocolate combined with the malty depth of Guinness is truly something else. I first made this for a St. Patrick’s Day party, and it was an absolute showstopper.

It looks so impressive, but I promise it’s one of the most straightforward and forgiving cake recipes I’ve ever made. The cake is unbelievably moist, and the Irish cream buttercream is the perfect sweet and creamy finish.

Ingredients

Here is what you will need for the cake and the luscious buttercream. Using room temperature ingredients for the wet components is key to a smooth batter.

For the Guinness Chocolate Cake:

1 ¾ cups all-purpose flour – The foundation of our cake. Be sure to measure it correctly to avoid a dry cake.
2 cups granulated sugar – Provides sweetness and helps create a tender crumb.
¾ cup unsweetened cocoa powder – Use a quality cocoa powder for a deep, rich chocolate flavor.
2 teaspoons baking soda – This is our primary leavening agent, which reacts with the acidic ingredients.
½ teaspoon baking powder – Provides an extra lift to ensure the cake isn’t too dense.
1 teaspoon fine sea salt – Balances the sweetness and enhances the chocolate notes.
¾ cup sour cream – The secret to an incredibly moist and rich cake. Full-fat yogurt works too.
½ cup vegetable oil – Contributes to the cake’s moist texture and tender crumb.
3 large eggs – Make sure they are at room temperature to help them mix evenly into the batter.
1 teaspoon vanilla extract – Adds a layer of aromatic warmth.
1 cup Guinness beer – The star ingredient that gives the cake its unique, deep, and malty flavor.

For the Irish Buttercream & Drip:

4 sticks unsalted butter – Should be at a cool room temperature (around 67°F) for the smoothest frosting.
6 cups powdered sugar – Sift this to avoid any lumps in your final buttercream.
¼ cup plus 2 tbsp Irish cream (like Bailey’s) – Adds that classic, creamy flavor to the frosting.
4 ounces semi-sweet chocolate, finely chopped – This will be for the decorative chocolate drip.
½ cup heavy cream – Used to create a smooth and pourable chocolate ganache for the drip.

Note: This recipe yields one 8-inch, two-layer cake, which serves about 12-16 people.

Variations

While this cake is fantastic as is, you can easily customize it. Here are a few ideas to get you started.

Non-Alcoholic Version: For the cake, you can use a non-alcoholic stout or even strong black coffee. For the buttercream, simply replace the Irish cream with heavy cream and add an extra splash of vanilla extract.
Different Frosting: If Irish cream isn’t your thing, this cake pairs wonderfully with a classic cream cheese frosting, a simple vanilla buttercream, or even a rich chocolate fudge frosting.
Add Chocolate Chips: For an extra layer of chocolatey goodness, fold a cup of semi-sweet or dark chocolate chips into the batter before baking.
Spice it Up: Add ½ teaspoon of cinnamon or a pinch of cayenne pepper to the dry ingredients to introduce a subtle warmth that complements the chocolate and stout.

Guinness Chocolate Cake With Irish Buttercream — Credit IG: soulfullymade_

Cooking Time

Prep Time: 20 minutes
Cook Time: 40 minutes
Total Time: 60 minutes (plus cooling time)

Equipment You Need

Two 8-inch Round Cake Pans: These are for baking the cake layers. Deep pans (3 inches) are best to prevent overflow.
Mixing Bowls: You’ll need a large one for the dry ingredients and a medium one for the wet ingredients.
Electric Mixer: A stand mixer or hand mixer is essential for making a light and fluffy buttercream.
Offset Spatula: This tool is your best friend for spreading frosting smoothly and creating clean edges.
Wire Cooling Rack: Crucial for allowing the cake layers to cool completely without getting soggy.

How to Make Guinness Chocolate Cake With Irish Buttercream?

This recipe comes together in a few distinct phases: making the batter, whipping up the frosting, and assembling the final masterpiece. Don’t be intimidated by the layers; the process is simple and rewarding. The key is to let your cake layers cool completely before you even think about frosting them.

Make the Cake Batter

First, preheat your oven to 350°F. Grease and line two 8-inch round cake pans with parchment paper. In a large mixing bowl, whisk together the flour, sugar, cocoa powder, baking soda, baking powder, and salt. In a separate medium bowl, whisk the sour cream, oil, eggs, and vanilla. Slowly pour in the Guinness and mix until just combined. Pour the wet ingredients into the bowl with the dry ingredients and stir with a spatula only until the batter comes together. Be careful not to overmix.

Bake and Cool the Cake

Divide the batter evenly between your two prepared cake pans. Bake for 35 to 40 minutes, or until a toothpick inserted into the center of the cakes comes out clean. Let the cakes cool in their pans on a wire rack for about 30 minutes. Then, carefully invert them onto the rack, remove the pans, and let them cool completely. For best results, you can wrap the cooled layers in plastic and chill them while you make the frosting; this makes them easier to handle.

Prepare the Buttercream and Assemble

In a large bowl, use an electric mixer to beat the room-temperature butter until it’s light and fluffy. Gradually add the sifted powdered sugar one cup at a time, mixing on low speed. Once incorporated, add the Irish cream and beat on high speed for about 3 minutes until the frosting is very smooth and airy. To assemble, place one cake layer on your serving plate and top with a generous amount of frosting. Place the second cake layer on top and apply a thin “crumb coat” of frosting all over the cake before chilling it for 20 minutes. Finish by frosting the entire cake with the remaining buttercream.

Add the Chocolate Drip

For the grand finale, place the chopped chocolate in a heatproof bowl. Heat the heavy cream until it simmers, then pour it over the chocolate. Let it sit for a few minutes, then stir until you have a smooth ganache. Let it cool for about 10 minutes until it has thickened but is still pourable. Carefully pour the ganache over the top of the chilled cake, using an offset spatula to gently nudge it over the edges to create drips.

Additional Tips for Making this Recipe Better

After making this cake more times than I can count, I’ve learned a few things that help ensure it turns out perfectly every time.

I always use room temperature eggs and sour cream. It really does make a difference in how well the batter comes together, resulting in a more even and tender crumb.
Don’t skip sifting the cocoa powder and powdered sugar. I know it feels like an extra step, but it’s the only way to guarantee you won’t have lumps in your cake or frosting.
When making the ganache drip, patience is key. If you pour it on the cake when it’s too hot, it will melt the buttercream. I test the consistency on the side of a cold glass to see how it will run.
For super clean slices, I run a large, sharp knife under hot water and wipe it clean between each cut. It makes the slices look professional and keeps the layers from smearing.

How to Serve Guinness Chocolate Cake With Irish Buttercream?

This cake is a statement piece on its own, so it doesn’t need much. Serve it at room temperature to ensure the buttercream is soft and the cake is moist. You can decorate the top with chocolate curls, a few festive sprinkles, or even a dollop of whipped cream on each slice. A drizzle of caramel sauce can also be a delicious addition. For a truly decadent dessert experience, pair a slice with a small glass of Irish cream on the rocks or a hot cup of coffee.

Nutritional Information

Here is an estimated nutritional profile for one slice of the cake.

Calories: ~650 kcal
Protein: 6g
Carbohydrates: 85g
Fat: 32g

Make Ahead and Storage

This is a great cake to prepare in advance, which is perfect for stress-free entertaining.

Make Ahead: The unfrosted cake layers can be baked, cooled, and wrapped tightly in plastic wrap. They can be stored at room temperature for up to two days or frozen for up to two months. The buttercream can also be made ahead and stored in an airtight container in the fridge for a week. Just let it come to room temperature and re-whip it before using.

Storing: Once frosted, the cake can be stored in a cake keeper at a cool room temperature for up to 3 days. The frosting seals in the moisture, keeping the cake fresh.

Freezing: You can also freeze individual slices. Wrap each slice in plastic wrap and then in foil. They will keep in the freezer for up to a month. Thaw them in the refrigerator or at room temperature before enjoying.

Why You’ll Love This Recipe?

This cake is more than just a dessert; it’s an experience. Here are a few reasons why you’ll fall in love with it.

Incredibly Moist and Fudgy: Thanks to the sour cream, oil, and Guinness, this cake has a texture that is unbelievably moist and rich. It’s the kind of cake that stays delicious for days.
Deep and Complex Flavor: The Guinness stout doesn’t make the cake taste like beer; instead, it deepens the chocolate flavor, adding complex, malty, coffee-like notes that are irresistible.
Surprisingly Easy to Make: Despite its impressive appearance, the cake batter comes together in one bowl without an electric mixer. It’s a straightforward recipe that delivers bakery-quality results.
The Perfect Special Occasion Cake: Whether it’s for St. Patrick’s Day, a birthday, or just a weekend treat, this cake is guaranteed to wow your friends and family. It’s decadent, unique, and absolutely memorable.