The BEST way to impart real Guinness flavor into chocolate cake is to reduce it down on the stove first. This packs in flavor without altering the cake’s texture. You can also prepare this chocolate layer cake as a sheet cake. See recipe Note.
- two 11.2–12-ounce (330–355ml) bottles of Guinness beer
- 1 and 3/4 cups (219g) all-purpose flour (spooned & leveled)
- 3/4 cup (62g) unsweetened natural cocoa powder
- 1 and 3/4 cups (350g) granulated sugar
- 2 teaspoons baking soda
- 1 teaspoon baking powder
- 1 teaspoon salt
- 2 teaspoons espresso powder (optional)
- 1/2 cup (120ml) vegetable oil (or canola oil or melted coconut oil)
- 3/4 cup (180g) full-fat sour cream, at room temperature
- 2 large eggs, at room temperature
- 2 teaspoons pure vanilla extract
- 1/2 cup (120ml) buttermilk*, at room temperature
- 8 ounces (224g) full-fat block cream cheese, softened to room temperature*
- 1/2 cup (115g) unsalted butter, softened to room temperature
- 2 and 1/2 cups (300g) confectioners’ sugar
- 1/2 cup (41g) unsweetened natural or dutch-process cocoa powder
- 3 Tablespoons (45ml) reduced Guinness, from step 1
- pinch salt
- optional: gold sprinkles for garnish
- Reduce the Guinness: In a large saucepan, bring the Guinness to a boil over medium-high heat. Once boiling, reduce to medium heat and allow to simmer until reduced down to about 3/4 cup, about 30 minutes. Begin making the cake batter once the Guinness is simmering. You’ll use 1/2 cup of the hot reduced Guinness in the cake batter, and set aside the rest to cool for the frosting. You can do this step 1 day ahead of time if needed—see Note.
- Preheat oven to 350°F (177°C). Grease two 9-inch cake pans, line with parchment paper rounds, then grease the parchment paper. Parchment paper helps the cakes seamlessly release from the pans. (If it’s helpful, see this parchment paper rounds for cakes video & post.)
- Make the cake: While the Guinness is simmering, whisk the flour, cocoa powder, sugar, baking soda, baking powder, salt, and espresso powder (if using) together in a large bowl. Set aside.
- Using a handheld or stand mixer fitted with a whisk attachment (or you can use a whisk) mix the oil, sour cream, eggs, and vanilla together on medium-high speed until combined. Add the buttermilk and mix until combined. Pour the wet ingredients into the dry ingredients, give it a quick mix/whisk, then add 1/2 cup (120ml) of hot reduced Guinness. Mix or whisk on low speed until the batter is completely combined. Batter is thin. If it helps, you should have about 6 cups or 1250g of cake batter total.
- Divide batter evenly between pans. Bake for 25–28 minutes or until a toothpick inserted in the center comes out clean. Baking times vary, so keep an eye on yours. The cakes are done when a toothpick inserted in the center comes out clean. (Note: Even if they’re completely done, the cooled cakes may slightly sink in the center. Cocoa powder is simply not as structurally strong as all-purpose flour and can’t hold up to all the moisture necessary to make a moist chocolate cake. It’s normal!)
- Remove the cakes from the oven and set on a wire rack. Allow to cool completely in the pans.
- Make the frosting: With a handheld or stand mixer fitted with a paddle attachment, beat the cream cheese and butter together on medium speed until creamy and smooth, about 2 minutes. Add confectioners’ sugar, cocoa powder, 3 Tablespoons (45ml) cooled reduced Guinness, and a pinch of salt. Beat on low speed for 30 seconds, then increase to high speed and beat for 1 full minute. Do not over-whip. Add a couple more Tablespoons of confectioners’ sugar or cocoa powder if frosting is too thin, or 1 more Tablespoon of cooled reduced Guinness if frosting is too thick. Taste. Add another pinch of salt if desired.
- Assemble and frost: If cooled cakes are domed on top, use a large serrated knife to slice a thin layer off the tops to create a flat surface. This is called “leveling” the cakes. Discard or crumble over finished cake. Place 1 cake layer on your cake stand or serving plate. Using a large icing spatula or small offset spatula, evenly cover the top with about 1 cup (about 250g) of frosting. Top with 2nd layer and spread remaining frosting all over the top and sides. A bench scraper is helpful for smoothing out the sides. I usually go lighter on the sides of the cake, to have leftover frosting for piping around the top. (Piping is optional.) If desired, garnish top of cake with sprinkles.
- Refrigerate uncovered cake for at least 30–60 minutes before slicing to help set the shape. After that, you can serve the cake or continue refrigerating for up to 4–6 hours before serving. Cake can be served at room temperature or chilled.
- Cover leftover cake tightly and store in the refrigerator for 5 days. I like using a cake carrier for storing and transporting.
- Make Ahead & Freezing Instructions: You can reduce the Guinness a day ahead of time. Let cool, cover, and refrigerate. Bring reduced beer to room temperature before using in the frosting, and heat 1/2 cup in the microwave or on the stove until hot to use in the cake batter. To make the cake ahead of time: Prepare cake through step 6. Wrap the individual baked and cooled cake layers tightly and refrigerate for up to 2 days or freeze up to 3 months. Bring to room temperature then continue with step 7. You can prepare the frosting 2–3 days in advance. Cover and refrigerate, then bring to room temperature before spreading onto/assembling the cake. Frosted cake freezes well, up to 3 months. Thaw overnight in the refrigerator, then bring to room temperature or serve cold.
- Special Tools (affiliate links): 9-inch Cake Pans | Electric Mixer (Handheld or Stand Mixer) | Glass Mixing Bowls | Whisk | Cake Turntable | Icing Spatula | Bench Scraper | Gold Shimmer Sprinkles | Cake Carrier (for storing)
- Cocoa Powder: Use natural cocoa powder in the cake batter, not dutch-process. (See dutch-process vs natural cocoa powder for more information.) Because there is no leavening occurring in frosting, you can use either natural or dutch-process in the frosting.
- Buttermilk: Buttermilk is required for this recipe. You can make your own DIY version of buttermilk if needed. Add 1 teaspoon of white vinegar or lemon juice to a liquid measuring cup. Then add enough room-temperature whole milk to the same measuring cup until it reaches 1/2 cup (120ml). (In a pinch, lower fat or nondairy milks work for this soured milk, but the cake won’t taste as moist or rich.) Stir it around and let sit for 5 minutes. The homemade “buttermilk” will be somewhat curdled and ready to use in the recipe.
- Amount of Cake Batter: This recipe (and the sour cream version) yields about 6 cups of batter, which is helpful if you need it for different Cake Pan Sizes & Conversions.
- Room Temperature Ingredients: All refrigerated items should be at room temperature so the batter mixes together easily and evenly. Read more about why room temperature ingredients are important.
- Why hot liquid? You want the reduced Guinness to be hot when you add it to the rest of the cake batter, to help the cocoa powder “bloom.” This makes for the best chocolate flavor.
- 9×13-Inch Pan: You can bake this cake as a sheet cake in a 9×13-inch baking pan. Same oven temperature, about 35–40 minutes bake time.
- Guinness Cupcakes: Here is my recipe for chocolate Guinness cupcakes with mocha Guinness buttercream.
Keywords: guinness chocolate cake