This Guinness Chocolate Cake is a rich, moist dessert with a deep chocolate flavor. The Guinness stout makes the chocolate taste even stronger and adds a slight bitterness that balances the sweetness. Topped with a marshmallow frosting, this cake becomes an irresistible treat, perfect for special occasions like St. Patrick’s Day.
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The billowy marshmallow frosting contrasts beautifully with the nearly black cake, resembling the frothy head of a pint of Guinness. For serving, pair it with a glass of Guinness or a shot of espresso for a perfect flavor complement.
Ingredients
Cake ingredients
Gather up the following ingredients to make the chocolate cake with Guinness:
- All-purpose flour and cocoa powder - sift both to remove any lumps
- Cornstarch, baking powder and baking soda
- Granulated sugar
- Eggs - use large eggs brought to room temperature
- Vegetable oil
- Guinness stout
- Simple syrup (optional) - simple syrup is brushed on cake layers to add moistness and more Guinness flavor. You need the following ingredients to make the syrup:
- Guinness stout
- Granulated sugar
See recipe card for quantities.
Buttercream and decorating ingredients
You need to the following ingredients to make the marshmallow fluff buttercream:
- Unsalted butter - softened to room temperature
- Powdered sugar - sift to remove any lumps
- Marshmallow fluff - most often found in your grocer's peanut butter aisle
- Whole milk or Guinness - you can enhance the stout flavor by incorporating Guinness into the buttercream
- Decorations - use your favorite decorations, such as sprinkles, glazes, or festive shamrocks, to add the perfect finishing touch!
See recipe card for quantities.
Instructions
Guinness chocolate cake instructions
First, prepare two 8" round cake pans by lining the bottom with parchment paper or greasing the pans. If you prefer a taller cake similar to the one I made, use two 7" round cake pans
The cake batter comes together effortlessly in a single bowl. You can mix it by hand or use an electric hand or stand mixer for convenience.
1 - Combine flour, cocoa powder, sugar, cornstarch, baking powder and baking soda in a large mixing bowl
2 - Add oil and eggs. Mix until well combined.
3 - Slowly pour Guinness into bowl while continuing to mix, scraping the bowl occasionally. The batter should be smooth.
4 - Divide batter between the two prepared cake pans. Bake at 350℉ / 177℃ for 35 - 40 minutes, or until cake is fully risen and a toothpick inserted in the center of cake comes out clean.
5 - After baking, place cakes on a rack and allow to cool completely before unmolding. Unmold by running an offset spatula or knife around the inside of the cake pan and flip the pan over onto a platter.
6 - Carefully trim the dome off of each cake to create a flat surface. Then, slice each cake in half horizontally for a total of 4 layers. Set the individual layers aside.
Guinness simple syrup instructions (optional)
This step is optional, but adding simple syrup enhances the moisture and intensifies the Guinness flavor. To prepare, combine granulated sugar and Guinness in a medium-sized saucepan. Bring the mixture to a gentle boil, stirring frequently until the sugar dissolves completely. Set aside to cool.
Buttercream and cake assembly instructions
1 - Place softened butter and marshmallow fluff in the bowl of a stand mixer (note: a hand mixer may also be used). Mix on medium speed until well combined (approximately 2 - 3 minutes).
2 - Add powdered sugar and milk (or substitute milk with Guinness to enhance the stout flavor) to mixing bowl. Turn on mixer to low speed. Gradually increase mixer to medium speed and mix for 2 minutes. Scrape down the mixer with a rubber spatula. Mix for another minute on medium-high speed.
3 - Place one cake layer on a serving platter. If using simple syrup, brush 3 - 4 tablespoons evenly over the cake layer. Spread a smooth, even ¼-inch layer of marshmallow buttercream on top.
4 - Spread a smooth, even ¼-inch layer of marshmallow buttercream on top.
5 - Gently place the second cake layer on top, ensuring it is centered and level. Brush with simple syrup if using. Spread a ¼" layer of marshmallow buttercream on top. Repeat process for remaining two cake layers.
6 - Cover the top and sides of the cake with a smooth layer of marshmallow buttercream. Decorate the cake as desired. For my design, I pressed sprinkles along the bottom edge, drizzled a green glaze over the top, and finished with buttercream swirls and candy shamrocks for a festive touch.
Equipment
Gather the following equipment to make this chocolate Guinness stout cake:
- Electric mixer (hand or stand)
- Bowls, measuring cups and spoons
- Two 8" Cake Pans - or use 7" cake pans if you wish for a taller cake
- Food Scale - optional for more accurate measurements
- Offset metal spatula
- Cake platter
- Saucepan - optional to make the Guinness simple syrup
Storage
To keep your Guinness chocolate cake fresh, store it in an airtight container in the refrigerator for up to five days. When you're ready to serve it, take the cake out about an hour beforehand so it can warm up to room temperature. This helps bring out its rich flavor and soft texture.
The finished cake does not freeze well due to the marshmallow buttercream.
FAQ
Guinness is a famous Irish dry stout that originated in 1759 at the St. James’s Gate Brewery in Dublin, Ireland. It is known for its dark color, creamy head, and rich, roasted malt flavor with hints of coffee and chocolate.
The bitterness of the stout balances the sweetness of the cake, creating a well-rounded taste. The roasted barley in Guinness gives hints of coffee and caramel, complementing chocolate beautifully.
Serve it with a scoop of vanilla ice cream or a drizzle of whiskey caramel sauce. Pair with a glass of stout, Irish coffee, or even a Irish cream liqueur.
More St. Patrick's dessert recipes
Looking for more dessert ideas for your St. Patrick's Day celebration? Check out these recipes:
I hope you enjoy this Guinness chocolate cake as much as my family and friends have over the years!
📋 Recipe
Guinness Stout Chocolate Cake
Equipment
- Hand Mixer or
- 1 Food Scale optional for more accurate measurements
- Bowls, measuring cups and spoons
- 2 8" Cake Pans or use 7" cake pans if you wish for a taller cake
- 1 Cake platter
- 1 Offset metal spatula
- 1 Saucepan optional - if making the simple syrup
Ingredients
Chocolate Guinness Cake
- ¾ cup Cocoa Powder
- 2 cups All Purpose Flour
- 2 cups Granulated Sugar
- 2 Tablespoon Cornstarch
- 2 teaspoons Baking Powder
- ½ teaspoon Baking Soda
- ¾ Cup Vegetable or Canola Oil
- 4 Large Eggs Room temperature
- 1 ¼ Cup Guinness Stout Room temperature
Simple Syrup
- ¾ Cup Guinness Stout
- ¾ Cup Granulated sugar
Buttercream
- 1½ Cup Unsalted butter Softened
- 16 Ounces Jar of Marshmallow Fluff
- 5 Cups Powdered sugar
- ¼ Cup Whole milk or Guinness stout using Guinness will add more stout flavor to the buttercream
Decorations - use any decorations to suit your theme (e.g. sprinkles, drizzle a glaze, candy shamrocks, etc...)
Instructions
Guinness Chocolate Cake
- Preheat oven to 350℉ / 177℃.
- Prepare two 8" round cake pans by lining the bottom with parchment paper or greasing the pans. Note: use 7" cake pans if you wish for a taller cake.
- Combine flour, cocoa powder, sugar, cornstarch, baking powder and baking soda in a mixing bowl. (note: the cake batter may be mixed by hand or using an electric mixer)
- Add oil and eggs. Mix until combined.
- Slowly pour Guinness into bowl while continuing to mix, scraping the bowl occasionally. The batter should be smooth.
- Divide batter between the two prepared cake pans.
- Bake for 35 - 40 minutes, or until cake is fully risen and a toothpick inserted in the center of the cake comes out clean.
- Place cakes on a rack and allow to cool completely before unmolding. Unmold by running an offset spatula or knife around the inside of the cake pan and flip the pan over onto a platter.
- Carefully trim the dome off of each cake to create a flat surface. Then, slice each cake in half horizontally for a total of 4 layers. Set the individual layers aside.
Simple Syrup (optional)
- Place granulated sugar and Guinness in a medium-sized saucepan. Bring mixture to a low boil, stirring often until the sugar is melted.
- Set aside and cool to room temperature.
Buttercream
- Place marshmallow fluff and softened butter in the bowl of a stand mixer (note: a hand mixer may also be used).
- Mix on medium speed until well combined (approximately 2 - 3 minutes).
- Add powdered sugar and milk (or Guinness if using) to mixing bowl.
- Turn on mixer to low speed. Gradually increase mixer to medium speed and mix for 2 minutes. Scrape down the mixer with a rubber spatula. Mix for another minute on medium-high speed.
Assemble Cake
- Place one cake layer on a serving platter. If using simple syrup, brush 3 - 4 tablespoons evenly over the cake layer. Spread a smooth, even ¼-inch layer of marshmallow buttercream on top.
- Gently place the second cake layer on top, ensuring it is centered and level. Brush with simple syrup if using. Spread a ¼" layer of marshmallow buttercream on top. Repeat the process for the remaining two cake layers.
- Cover the top and sides of the cake with a smooth layer of marshmallow buttercream, ensuring even coverage for a polished finish.
- Decorate cake as desired. For my design, I pressed sprinkles along the bottom edge, drizzled a green glaze over the top, and finished with buttercream swirls and candy shamrocks for a festive touch.
Video
Notes
- To keep your Guinness chocolate cake fresh, store it in an airtight container in the refrigerator for up to five days. When you're ready to serve it, take the cake out about an hour beforehand so it can warm up to room temperature. This helps bring out its rich flavor and soft texture.
Vince says
I had the pleasure of having a slice of this gem, and the combination of tastes is great. The chocolate cake is a treat - it's a cut above other chocolate cakes I've had, and I'm guessing the Guinness makes the difference.
There was a suggestion to try it with vanilla ice cream, and I'm on board with that. Give it a try. You will have a new favorite.
dessertswithstephanie says
Vince, Thank you for your feedback! So pleased you enjoyed the cake.