St. Patrick’s Day has always been my favorite excuse to bake something indulgent—and this Guinness Chocolate Cake with Irish Buttercream? Oh, it’s the star of every celebration. I remember the first time I tried adding stout to chocolate cake—it was an experiment, really. I’d heard whispers about how Guinness deepens the flavor, but wow, I wasn’t prepared for just how magical it would be. The malty richness of the beer mingles with cocoa to create something almost truffle-like, while the Irish buttercream—soft, sweet, and just a little tangy—melts into every bite like a cloud. And here’s the best part: it’s shockingly easy to make. No fancy techniques, no hard-to-find ingredients—just a bowl, a saucepan, and a whole lot of deliciousness waiting to happen. Whether you’re hosting a party or just treating yourself (no judgment here!), this cake turns any March 17th into a proper feast.
Why You’ll Love This Guinness Chocolate Cake with Irish Buttercream
This isn’t just any chocolate cake—it’s a showstopper that’ll have everyone asking for seconds (and the recipe!). Here’s why it’s become my go-to for St. Patrick’s Day:
Rich, Decadent Flavor
The Guinness works magic here—it deepens the chocolate flavor without screaming “beer!” The result? A cake that tastes like the fanciest dark chocolate you’ve ever had, with this subtle malty backbone that makes it impossible to stop eating. Pair that with the silky Irish buttercream (made with real Irish butter—trust me, it matters), and you’ve got dessert heaven.
Festive and Unique
Sure, you could bring green cupcakes to the party… or you could arrive with this beauty that actually celebrates Irish flavors. The stout gives it this gorgeous dark color that looks stunning under a snowy blanket of buttercream. It’s unexpected but feels perfectly at home on a St. Paddy’s table—plus, it’s way more exciting than another batch of sugar cookies shaped like clovers!
Ingredients for Guinness Chocolate Cake with Irish Buttercream
Gather these simple ingredients—they’re the backbone of this unforgettable cake. Pro tip: measure everything before you start! Trust me, it makes the whole process smoother when you’re not digging through cabinets mid-batter.
- 1 cup Guinness stout (yes, drink the rest—I won’t tell)
- 1 cup unsalted butter, plus extra for greasing
- 3/4 cup cocoa powder (use the good stuff—it shows)
- 2 cups all-purpose flour, spooned & leveled
- 1 1/2 tsp baking soda (check it’s fresh!)
- 3/4 tsp salt (balances the sweetness)
- 2 large eggs, room temperature
- 2/3 cup sour cream (full-fat for extra moisture)
- 1 cup Irish butter, softened (Kerrygold is my favorite)
- 4 cups powdered sugar, sifted
- 2 tbsp heavy cream
- 1 tsp vanilla extract (real, not imitation!)
2 cups granulated sugar
How to Make Guinness Chocolate Cake with Irish Buttercream
Okay, let’s dive in! Don’t let the fancy name fool you—this cake comes together in simple steps. Just follow along, and you’ll have a showstopper that tastes like it took way more effort than it actually did.
Preparing the Cake Batter
First, grab your favorite saucepan (mine’s a bit battered—pun intended). Pour in the Guinness and butter, then warm it over medium heat until the butter melts. Whisk in that cocoa powder until it’s silky smooth. Oh, that smell? Pure chocolatey magic. Let it cool slightly—you don’t want scrambled eggs in your batter!
While that’s cooling, whisk together your dry ingredients—flour, sugar, baking soda, and salt—in a big bowl. In another bowl, beat the eggs and sour cream until they’re best friends. Now, slowly pour in your slightly cooled Guinness mixture, whisking as you go. Finally, gently fold the wet into the dry ingredients. A few lumps are fine—overmixing is the enemy of a tender crumb!
Baking and Cooling
Pour that gorgeous dark batter into your greased pan (I like to line the bottom with parchment for extra insurance). Slide it into a 350°F oven and set your timer for about 35 minutes. The cake’s done when a toothpick comes out with just a few moist crumbs—not wet batter, but not bone-dry either.
Here’s where patience pays off: let the cake cool completely in the pan. I know, I know—the smell is torture. But if you frost a warm cake, you’ll end up with a melty, sad mess. Trust me, I learned this the hard way. Use the waiting time to… uh… “dispose” of that leftover Guinness.
Making the Irish Buttercream
Time for the crowning glory! Beat that softened Irish butter (yes, it must be Irish—it’s creamier and richer) until it’s pale and fluffy. Now, add the powdered sugar gradually—unless you enjoy sugar clouds all over your kitchen. Splash in the cream and vanilla, then whip it until it’s so light, you could float away on it.
Once your cake’s cool, spread that dreamy buttercream thickly over the top. No fancy piping needed—I love the rustic “just swiped it on” look. The contrast of the dark cake and snowy frosting is stunning. Slice, serve, and prepare for applause!
Tips for the Perfect Guinness Chocolate Cake with Irish Buttercream
After dozens of batches (and happy taste-testers), I’ve picked up a few tricks to make this cake foolproof. First, room-temperature ingredients matter—cold eggs or butter can make your batter seize up. Second, when mixing the batter, stop as soon as the flour disappears—overmixing leads to toughness. And my secret weapon? A splash of espresso powder in the dry ingredients. It doesn’t make it taste like coffee, just deepens the chocolate flavor even more. Oh, and don’t skip the parchment paper lining—nothing ruins a celebration like a stuck cake!
Serving and Storing Guinness Chocolate Cake with Irish Buttercream
This cake deserves a little ceremony—I love serving thick slices with strong black coffee or a glass of cold milk to balance the richness. For the full Irish experience? A wee dram of whiskey on the side works wonders too! The cake keeps beautifully at room temperature under a cake dome for 2 days, or refrigerate (covered) for up to 5 days. Just let it sit out for 30 minutes before serving—cold buttercream is no one’s friend. If you’re feeling fancy, warm slices for 10 seconds in the microwave—the buttercream turns into a decadent sauce!
Nutritional Information
Each generous slice of this cake (hey, we don’t do skinny slices here!) packs about 450 calories – mostly from all that good butter and sugar. You’re looking at 22g fat, 60g carbs, and just a smidge of protein to balance things out. Now, full disclosure: my “slices” might be… generous. Your exact numbers will vary based on how thick you frost it (no judgment if you go heavy—I always do!). This is indulgent holiday baking, friends—save the calorie counting for January!
FAQs About Guinness Chocolate Cake with Irish Buttercream
Over the years, I’ve gotten the same excited questions from friends who’ve tried this cake. Here are the answers to the ones that pop up most—so you can bake with confidence!
Can I Use a Different Stout?
Absolutely! While Guinness is my go-to (that iconic creamy head blends beautifully into the batter), any dry stout will work. Murphy’s or Beamish are great Irish alternatives. Just avoid chocolate or coffee stouts—they can overpower the cake’s balance. And no, light beer won’t cut it—you need that rich, malty depth only a proper stout provides.
How Do I Prevent Dry Cake?
Three words: don’t overbake it! Set your timer for the lower end of the range (35 minutes) and check early. The cake keeps baking as it cools, so pull it when the toothpick has a few clinging crumbs. Also, measure your flour correctly—scooping packed cups leads to dryness. Spoon and level, friends! That sour cream? It’s your moisture insurance—never skip it.
Can I Make This Cake Ahead?
You bet! The flavors actually deepen overnight. Bake the cake, let it cool, then wrap tightly in plastic. Frost it the next day—the buttercream takes 10 minutes tops. The frosted cake holds beautifully at room temperature for a day, or refrigerate for up to 3 days (just bring to room temp before serving).
Share Your Guinness Chocolate Cake with Irish Buttercream
I’d love to hear how your cake turns out! Snap a photo of your masterpiece (or that first glorious slice) and share it—tag me so I can cheer you on. Questions? Tips of your own? Drop them in the comments. Now go enjoy that cake—you’ve earned every delicious bite! If you want to see more of my baking adventures, check out my Pinterest page for inspiration.
