Guinness Chocolate Cake with Irish Buttercream

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This Guinness Chocolate Cake with Irish Buttercream recipe involves chocolate AND booze. It doesn’t get much better than that!

What better way to celebrate St. Patrick’s Day? Or just any day, really. Because some days require chocolate and Bailey’s. And that might be because you’re celebrating something great… or because it’s been a long day.

The chocolate cake component of this recipe is super simple. You don’t even need an electric mixer for the cake batter! So you only have to clean your stand mixer bowl once (for the frosting).

The cake base contains sour cream to give the cake a ton of richness and moisture, and the Guinness stout beer gives it a deep, roasted, slightly coffee-like taste that pairs so wonderfully with that rich chocolate flavor.

Feel free to get creative with decorating this cake! We went for a ‘naked’ look where the sides of the cake peek through the frosting. That focuses the attention on that beautiful chocolate ganache drip topping. You could go crazy with green food coloring, shamrock sprinkles, or gold coins for a fun, festive look.

Or keep it classic with chocolate shavings or even a drizzle of salted caramel for an extra tasty garnish.

How to Make Guinness Chocolate Cake with Irish Buttercream

How to Make MOIST Chocolate Cake

Be very careful not to accidentally over-measure the flour and cocoa powder in this recipe. This will lead to dense, dry, or tough cake. The best way to ensure this never happens is to measure your ingredients by weight using a digital kitchen scale. This will forever improve your baking! If you don’t have a scale, be sure to use the spoon and level method to measure your dry ingredients.

How to Prevent Your Chocolate Cake from Sinking

This is an extremely moist and rich cake recipe, so if your cake does sink slightly in the center don’t worry. It’s definitely not ruined! Simply use a serrated knife or cake leveler to level off the cake for a flat layer. To prevent your Guinness Chocolate Cake from sinking in the first place, check out my tips below:

1. Make sure your oven is at the correct temperature. Many home ovens actually run much hotter or colder than they say. Learn more about this here.
2. Check that your baking powder & soda are fresh. These leavening agents are crucial to helping your cake rise, and can actually lose their effectiveness long before the date printed on the packaging. Learn more about that here.
3. Be sure to measure all ingredients properly. As mentioned above, I love my digital kitchen scale to ensure precision! Learn more about weighing ingredients here.
4. Avoid over-mixing the batter. Over-mixing the batter can make your cake tough and rubbery and cause it to sink.
5. Bake the batter soon after mixing it up. Don’t let the batter sit for any longer than necessary before baking, as this can cause the leavening agents to lose their effectiveness, and your cake may sink, or it may never rise in the first place!
6. Bake in the center of your oven and don’t open the oven door unnecessarily, to ensure your oven maintains the most even heat possible.
7. Don’t underbake the cake. A cake tester or toothpick should come out clean!
8. More tips for how to prevent cakes and loaves from sinking in this article.

What Cake Pan do I Need for This Cake?

This Guinness Chocolate Cake with Irish Buttercream recipe was written to use two 8-inch pans. These Fat Daddios pans are my favorites. Be sure to use pans that are deep enough (I recommend 3 inches) to avoid your cake spilling over.

Can I Bake This with Different Sized Baking Pans?

Probably! You’ll just need to do a little math to adjust the timing and calculate the volume. Check out Wilton’s handy guide for converting cake baking pans.

Can you Bake This Cake into Cupcakes?

Almost any cake recipe can be made into cupcakes. Check out my full guide on how to convert cake into cupcakes (and vice versa!). 

Tips for Perfect Bailey’s Irish Cream Buttercream

1. Butter temperature. Be sure your butter is at a cool room temperature, about 67°F, so it blends into a smooth buttercream icing.
2. Use finely ground powdered sugar. Not sure if you’ve got the right sugar? Check out my post on 6 Secrets to Perfect Buttercream.
3. Whatever you do, don’t skip sifting the sugar! If you skip sifting your powdered sugar, you will end up with unattractive lumps and bumps in your iced cake.
4. Irish Cream substitutes. If you’d prefer to keep this recipe free of any un-cooked alcohol, feel free to replace the Irish Cream with regular heavy cream.

How to Make the Perfect Chocolate Ganache Drip

There are a few ways to make your ganache drip, but here’s how I like to do it:

1. Firstly, be sure your cake is cold. Allow it to chill in the refrigerator until the buttercream is chilled and firm to the touch before applying the ganache drip.
2. Also, be sure that your ganache isn’t too hot, as this will melt the buttercream and run straight off the cake. Test the consistency of the drip by pouring a tiny bit down the side of a glass.
3. Place the cake on a cake turntable, so you can easily turn the cake as needed. This is especially helpful when applying the drips down the sides of the cake.
4. Carefully pour some of the ganache over the top of the chilled cake. Use an offset spatula to quickly smooth the ganache over the top of the cake before it sets, spreading evenly just to the cake’s edge.
5. Use a squeeze bottle to gently squeeze one drip at a time down the sides of the cake.
6. Before the ganache fully sets, add sprinkles, chocolate curls, or any other decor you like. It won’t adhere properly if you allow the ganache to firm up before adding.

How to Make Guinness Chocolate Cake Ahead of Time

You can wrap unfrosted, un-cut, cooled cake layers completely in several layers of plastic wrap. Place inside a freezer bag. Store at room temperature for up to 4 days or freeze for up to 2 months. Defrost overnight in the fridge (do not defrost at room temperature or you will end up with mushy cake).

How to Store Guinness Chocolate Cake with Irish Buttercream

Since frosting acts as a protective seal that keeps the cake moist and fresh, frosted cakes can be stored at a cool, dry room temperature for 2 to 3 days. Especially this frosting, since it has some alcohol content to further preserve. Cover with a cake keeper to keep the frosting and decorating intact. Don’t use plastic wrap, which will not only ruin your frosting, but also create condensation that can cause the frosting to separate.

More Chocolate Cake Recipes

• Best Chocolate Cake
• Nutella Cake
• Chocolate Zucchini Cake
• Chocolate Bundt Cake
• Chocolate Mint Cupcakes 

More St. Patrick’s Day Recipes

• Chocolate Peanut Butter Whiskey Truffles
• Frozen Mint Chocolate Chip Pie
• Bailey’s Cheesecake Bars
• Mint Chocolate Whoopie Pies

Find ALL my St. Patrick’s Day recipes here!

This recipe was originally published in 2014 and recently updated with weight measurements and new photos. Photos by Ashley McLaughlin.