If you don’t already keep up with me on Instagram, you are seriously missing out on the opportunity to vote for what recipes you’ll see next! When I’m brainstorming or planning my content calendar, the most important thing is whether or not you guys actually want to see what I have in mind. So, I’ll often do little YES/NO survey on my IG story. And let’s just say this one layer Guinness chocolate cake got a LOT of yeses.
This blog is no stranger to rich chocolate desserts. It’s got a double chocolate skillet cookie, a chocolate sheet cake, and these romantic AF chocolate cupcakes. And with St. Patrick’s Day around the corner, this cake is a perfect boozy addition to our chocolate collection!
Ohhhhh, this cake.
It’s the stuff of dreams. It’s finger lickin’ good: moist and rich with a tender crumb, topped with a perfect chocolate buttercream frosting. This is the cake you take home to meet the parents. This is the cake that makes my picky eater nephew ask for seconds and thirds!
Do you think making an incredible chocolate cake is hard? That you’ll need tons of ingredients and hours in the kitchen? Once, I thought that too.
But, thankfully, it isn’t so!
One layer Guinness chocolate cake has a simple ingredient list and easy baking technique! In fact, the only time you’ll need your mixer is when you’re making the frosting.
Oh, and about that frosting.
It’s chocolate buttercream. It’s freaking amazing. Silky, rich, and, most importantly, not sickeningly sweet.
Can you say #blessed?
What is Guinness chocolate cake?
AKA chocolate stout cake, it’s simply a moist chocolate cake made with Guinness beer.
But don’t be deceived: it doesn’t taste like straight up beer! Guinness is used simply to deepen and enhance the cake’s flavor. It is similar to how coffee or espresso powder is used in chocolate cakes.
Ingredients for one layer Guinness chocolate cake
- All purpose flour – Simple AP flour is best to use. Cake flour is too light.
- Unsweetened cocoa powder – For chocolate flavor. I’ve tried this recipe using both cocoa powder and melted chocolate, but found that using both made the texture too brownie-like. Use natural cocoa powder, not Dutch-process.
- Salt – A tiny amount to balance the sweetness.
- Granulated sugar – Plain white sugar is all we’ll need. I haven’t tried this recipe with brown sugar, but it should work fine as a substitute.
- Baking soda – Acts as a leavening agent since we’re using acidic ingredients like cocoa powder and sour cream.
- Egg – For structure and richness. Be sure to use room temperature egg.
- Vanilla extract – Acts as a flavor enhancer. I’d never trust a cake recipe without at least a splash of vanilla.
- Guinness beer – The star of the show! I used Extra Stout Guinness. Canned and bottled are both fine.
- Sour cream – For extra moisture; since cocoa powder tends to make baked goods drier, think of the sour cream as insurance. It also adds tang.
- Vegetable oil – It’s usually much easier to make a moist cake with oil rather than butter. Plus,you won’t have to pull out your mixer to do any creaming. You won’t even miss the butter taste because we’ve got enough Guinness and sour cream to make up for its absence!
How to make chocolate cake from scratch
We can break down the cake-baking process into five simple steps:
- Preheat the oven to 350 degrees F. Grease and line an 8 inch cake pan (round or square) with parchment paper.
- Prepare the dry ingredients: whisk flour, cocoa powder, salt, sugar, and baking soda together in a large mixing bowl. Set aside. Prepare the wet ingredients: mix egg, vanilla, sour cream, beer, and oil in a separate mixing bowl and set aside.
- Combine: pour the wet ingredients into the dry ingredients, and use a rubber spatula to gently fold them together until just combined. It’s very important that you do not over mix.
- Pour the batter into the prepared cake pan and bake for about 30-35 minutes. My preferred way to check cakes for doneness is to use my index finger. Touch the center of the cake with your finger; if the center is soft and springs back, your cake is finished and can be removed from the oven.
- Let the cake cool in the pan for about 15 minutes. Use a knife to gently lift the edges of the cake away from the pan. Flip the pan upside down to ease the cake onto a wire rack. Cool completely, about an hour, before frosting.
Cake Baking Tips:
I always say that baking doesn’t have to be frustrating or complicated if you just follow the rules. Cakes are actually pretty straight forward, but just the slightest mistake can have a big effect on the outcome of your baked good.
Here are some tips to help you make the most of your cake baking:
- Use room temperature ingredients – Room temperature ingredients are easier to incorporate together to make a cake with a good texture. Let your eggs and Guinness rest out of the refrigerator for about an hour to come to room temperature.
- Use high quality ingredients – I’m a baking snob, so I will only use certain brands of flour/cocoa powder/butter in my sweets. You’re going to get a better result with King Arthur’s AP flour than a random great value brand you pick up just anywhere. It sounds kind of harsh, but it’s true!
- Fresh leavening agents – Baking soda does expire and lose its potency after about six months after opening. When this happens, your baked goods may not rise as well. Be sure to use fresh leavening agents. If it’s been sitting in your cupboard for longer than you can remember, it’s probably time to get a new one.
- Digital scale – Not only does using a digital kitchen scale give you the most accurate measurements for ingredients like flour, it can also help reduce the amount of dishes you’ll have to clean!
- Don’t over-mix – When you combine the wet and dry ingredients, use a rubber spatula to gently fold and mix them together until they are just combined. Meaning, no huge dry streaks of flour. If you keep mixing after that point, you’re likely to end up with a dense, gummy cake.
- Don’t forget it – As in, don’t put your cake in the oven, then fall asleep to Netflix. One of the biggest culprits of dry, crumbly cake is over baking. So, be sure to set your timer and be attentive. In fact, I always check my cakes at least five minutes before the finish time stated in the recipe.
How to make chocolate buttercream
We’ll be using an easy chocolate buttercream frosting recipe from the always reliable Sally.
At first, I was very hesitant about pairing this cake with buttercream, as I find most too sweet for my liking. But I also felt that going for the usual chocolate ganache would be a bit too boring.
This chocolate frosting, however, is absolutely perfect. It’s delicious and decadent without being overly sweet. Sally never really disappoints us, does she?
Plus, you’ll only need six ingredients: unsalted butter, confectioners’/powdered sugar, cocoa powder, milk, salt, and vanilla. Here’s how to make this frosting:
- Beat softened butter and salt on medium speed until light and creamy.
- Add cocoa powder, sugar, milk, and vanilla, then beat on low speed until fully incorporated with the butter. The frosting will be nice and sturdy, as well as fluffy.
See how simple that is? And so much better than the store bought stuff!
Answering your buttercream questions
Does it matter what kind of butter is used?
-Absolutely! Buttercream has so few ingredients, so the quality of what you use really really matters. Firstly, you’ll want to use unsalted butter so you have complete control over the flavor of your frosting. Secondly, you’ll want to use the best butter you can find. I swear by Land O’ Lakes.
Can I make buttercream frosting ahead of time?
-Hell yeah. You’ll save some time and it’s super convenient.
Does buttercream frosting need to be refrigerated?
-Not necessarily. The American kind, simply made with butter and sugar, will last in the fridge for about 2 weeks, but you can store it in an airtight container in a cool area for up to 2 days.
Make Ahead & Storage
Both the cake and frosting can be made ahead. The un-frosted cake will keep for up to 5 days at room temperature when covered in plastic wrap and stored in a ziploc bag. The frosting is good for up to 2 days at room temperature and up to 2 weeks in the refrigerator.
If you wish to store the frosted cake for later enjoyment, cover it with a cake keeper for up to 5 days.
Craving something healthier?
-Try my vegan chili recipe
-Or this amazing chickpea curry
One Layer Guinness Chocolate Cake
- 1 and 1/2 cups (180 grams) all purpose flour
- 1/2 cup (42 grams) unsweetened cocoa powder (not Dutch-process)
- 1 teaspoon baking soda
- 1/4 teaspoon salt
- 1 and 1/4 cup granulated sugar
- 1 large egg room temperature
- 1 tablespoon vanilla extract
- 1/4 cup sour cream room temperature
- 3/4 cup Guinness stout beer room temperature
- 1/3 cup vegetable oil
- Preheat the oven to 350 degrees F. Grease and line an 8 inch round cake pan with parchment paper.
- In a large bowl, whisk together flour, cocoa powder, baking soda, salt, and sugar. In a separate bowl, mix egg, vanilla, sour cream, Guinness, and vegetable oil together until completely combined and smooth. Pour the wet mixture into the dry mixture; fold gently with a rubber spatula until just combined. Be careful not to over mix.
- Pour the batter in the prepared pan and bake for 30-35 minutes, or until the center of the cake springs back when gently touched with your index finger. Remove from the oven. Let the cake cool in the pan for 15 minutes, before transferring to a wire rack to cool completely.
- To make the chocolate buttercream, follow this recipe by Sally's Baking Addiction: https://sallysbakingaddiction.com/favorite-chocolate-buttercream/. Let the cake cool for at least a full hour before frosting.
- You can use an 8 inch square cake pan, if desired.
- Nutrition facts are just an estimate.