Published: Mar 11, 2021 · Modified: Feb 27, 2023 by Amanda McGrory-Dixon

Irish Whiskey Chocolate Cake With Baileys Mousse

Indulge in complete decadence with this Irish whiskey chocolate cake! Each layer of fluffy, moist chocolate cake is filled with a delicate, airy Baileys mousse and then covered in rich chocolate ganache frosting. This whiskey-flavored chocolate cake is one show-stopping dessert that will leave your guests wowed.

A slice of Irish whiskey chocolate cake on a wooden plate with a bottle of Jameson behind it.

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Why You Need to Make This Recipe
Ingredients
Step-by-Step Instructions
Recipe FAQs
Expert Tips
Perfect Pairing
Looking for More St. Patrick’s Day Recipes?
📖 Recipe

Why You Need to Make This Recipe

Get ready to swoon. Sure, a basic chocolate cake is always delicious, but when you add a little Irish whiskey? It's the boozy chocolate dessert we all need in our lives.

After one bite, your toes will curl, and your eyes will slowly close as you take in that explosion of chocolate with complex whiskey notes. Don't be surprised when everyone hails you as the ultimate cake baker and asks you to make this treat for just about every get-together.

Fortunately, this chocolate dream is perfect for any occasion. Obviously, this makes a wonderful St. Patrick's Day cake, but we don't have to reserve it just for that holiday.

Have a whiskey lover in your life? This would be their perfect birthday cake. Looking for a chocolatey dessert for Christmas? You found it right here.

Make sure you keep this Irish whiskey chocolate cake recipe handy because it's a tried and trusted recipe you'll want to make over and over again.

Ingredients

If you've ever baked a homemade chocolate cake, these ingredients should look common to you. Of course, Irish whiskey is our signature flavor and different from your standard chocolate cake. For those who aren't big Irish whiskey drinkers, you can't go wrong using Jameson here.

I also like to use Hershey's Special Dark for the cocoa powder. This is a Dutch-processed cocoa powder, which I find produces a richer, more fudgy cake. Both natural and Dutch-processed cocoa powder work with this recipe, but I give the nod to the Dutch here.

You'll also noticed in the recipe card I specify dark brown sugar rather than light brown sugar. While you can substitute light brown sugar, the dark brown variety has more molasses. I love the deeper flavor it adds.

Step-by-Step Instructions

Before starting on our cake, we want to make the Baileys mousse and chocolate ganache frosting. My Baileys mousse is already detailed on the blog, so you can visit the link if you'd like step-by-step photos.

Make the Frosting

Let's move on to our frosting. Essentially, chocolate ganache frosting is simply chocolate ganache that has had time to cool and thicken, so it needs a little time to sit, which is why I like to start this recipe first.

Step 1: The process to make this frosting is as easy as it gets. We first add chopped chocolate to a bowl (photo 1).

Step 2: Meanwhile, we bring heavy cream to a simmer, pour it all over the chocolate and let the mixture sit for five minutes (photo 2).

Step 3: Now we stir the chocolate and cream. At first, it will look like a lot of heavy cream, and you might be worried that the mixture will never come together (photo 3). But keep stirring, and you will eventually get beautifully smooth ganache like so (photo 4).

A collage showing the process of how to make the chocolate ganache frosting.

Make the Cake

Step 1: To prepare our dry ingredients, we stir together flour, salt, baking soda, baking powder, the sugars, espresso powder and cocoa powder (photo 5).

Stirring together the dry ingredients in a large mixing bowl until everything combines.

Step 2: In the same bowl, we add our eggs, buttermilk, oil and vanilla (photo 6) and beat the mixture on medium speed for a couple minutes until it's shiny and smooth (photo 7).

A collage showing the process of incorporating the wet ingredients in the dry ingredients in a large mixing bowl.

Step 3: Now we stir in our Irish whiskey, but before we do that, we need to heat it up. With homemade chocolate cake, it's common to use a hot liquid, such as boiling water or freshly brewed coffee. Known as blooming, this helps dissolve the cocoa powder for more intense flavor, so we're doing the same thing here by heating our whiskey.

I like to take care of this step by heating the whiskey in the microwave. The exact time varies by microwave, but a minute or two should do the trick.

The whiskey will leave us with a thin batter, so don't fret. That's completely normal. See that thin drizzle (photo 8)?

The thin batter drizzling off the beater into the mixing bowl.

Step 4: Now that our batter is prepared, we're ready to divide it among three 8-inch pans, bake and cool on wire racks (photo 9).

The batter poured into three different round cake pans on a marble surface.

How to Assemble

Step 1: With our cake cooled, we’re ready to assemble. We place one cake layer on our serving tray and spread about half the Baileys mousse on top (photo 10).

Spreading the Baileys mousse in between the layers of cake.

As you can see from earlier photos, this gives us a larger layer of mousse, which I love. That said, you can use less if you want. There isn’t a right or wrong here — it all comes down to personal preference, so that’s why I don’t give an exact measurement.

Step 2: Now we place the second cake on top and repeat with the chocolate mousse. We then put the third layer on top of that, and now we’re ready to coat it with the chocolate ganache frosting (photo 11).

Spreading the chocolate ganache on the chocolate cake.

Step 3: By now, the chocolate ganache frosting should be nice and spreadable. It will continue to firm as it sits. If you’d like, you can even use some extra ganache to pipe little puffs on top for decoration.

And just like that, our cake is assembled, and we’re ready for one big slice of chocolate decadence.

Recipe FAQs

Does this cake need to be refrigerated?

Because of the mousse filling, I recommend keeping the cake refrigerated. That said, the cake is best served at room temperature.

The chill from refrigerating dilutes the flavor a bit, but simply allowing the cake to sit for about 20 minutes in room temperature before serving is all we need to enjoy that chocolatey goodness in each bite. Of course, I have eaten this cake straight out of the refrigerator and enjoyed it, but you'll love it even more if you give it a chance to come down in temperature.

How long will it keep?

I think chocolate cake is at its best when fresh, so I try to bake it within a day of serving. However, this cake is moist enough that it will still be great for a good three to four days. After that, the mousse may start to lose its structure.

Expert Tips

If you'd like, you can make the Baileys mousse the day before the cake. This is what I do as I prefer to divide up the processes.
When measuring your flour, cocoa powder and sugar, do not scoop your measuring cup. Instead, spoon the ingredients into your measuring cup and use a butter knife to level. Scooping results in overpacking.
The batter will taste heavy on the Irish whiskey and have a bite, but once it bakes, that bite will disappear, and you'll just be left with delicious whiskey flavor. So don't panic if it tastes too strong in batter form.
If you forget to set your eggs out in room temperature, you can speed up the process by placing the eggs in warm -- not hot -- water for about 10 minutes.
While I highly recommend the Baileys mousse as a filling, you can also use the chocolate ganache between layers instead if you're short on time. I've made this cake with just chocolate ganache, and it was fabulous that way as well.
Make sure to check the expiration dates on your baking soda and baking powder. You absolutely must replace them if they're expired.
Do not open the oven door before you're ready to test the cake's doneness. This can leave you with a sunken middle.

The Irish whiskey cake on a marble dessert stand with greenery on the side and a bottle of Jameson.

Perfect Pairing

Imperial stouts are so delicious with whiskey that they're often aged in whiskey barrels. So it only makes sense that an imperial stout would be perfect with this cake. Because imperial stouts have a high ABV, they tend to show off some residual sweetness that makes them great with desserts. A Baltic porter is also a lovely option with any kind of chocolate sweet.

For a wine, a port is always wonderful with chocolate cake. The two are a classic pairing, and you can't go wrong here.

Or maybe you're craving a festive cocktail — my Baileys chocolate martini is as perfect as it gets. You'll also love my Irish mule, Baileys Irish coffee martini or Irish whiskey smash. This espresso martini from Texanerin Baking is another delightful option.

When not just any cake will do, I hope you try this Irish whiskey chocolate cake. You will love every indulgent bite.

Cheers!

Looking down at a slice of Irish whiskey chocolate cake on a wooden plate with the greenery.

Looking for More St. Patrick’s Day Recipes?

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Irish Whiskey Chocolate Cake With Baileys Mousse

Why You Need to Make This Recipe

Ingredients