Easy Guinness Chocolate Cake with Irish Cream Buttercream Frosting

Saint Patrick's Day has always been one of my favorite holidays! The traditions, the vibrant green, and the playful leprechaun mischief all make it so much fun. Last year, I created this Guinness Chocolate Cake recipe, and it was an instant hit, so I’m excited to share it with you! The cake is a rich, moist blend of chocolate and Guinness Stout, topped with a smooth, Irish Cream buttercream frosting. It’s the perfect treat to impress your family and friends this St. Patrick’s Day!

JUMP TO RECIPE

Guinness Chocolate Cake

Why Guinness Chocolate Cake Will Become A ST. Patrick's Day favorite

1. Colorful and festive: Have fun with the Saint Patricks Day theme, pipe a pot of gold, have fun creating with rainbow sprinkles, or add no color and just pipe the top with some Irish buttercream rosettes!

2. Chocolate, Guinness, and Irish Cream: My husband's birthday is March 19th so I made this for him last year and it was a hit. You cannot go wrong with the magic trio of chocolate, Guinness, and Irish Cream.

3. Delicious: This cake is so moist and has the perfect balance of adult beverage to chocolate ratio :)

   
   
   
   

   

   Guinness Chocolate Cake

   
   

Ingredients for Guinness Chocolate Cake

• 2 sticks unsalted butter, melted

• 1 cup Guinness beer

• ¾ cup cocoa powder

• 2 large eggs

• ¾ cup buttermilk

• 1 Tbsp vanilla extract

• 2 cups all-purpose flour

• ¾ cup granulated sugar

• ½ cup brown sugar

• 1 ½ tsp baking soda

• ½ tsp salt

  
  

Ingredients for Irish Cream Buttercream

• 3 oz Irish Cream whiskey

• 2 sticks unsalted butter, softened

• 4 cups powdered sugar

• Green food coloring

• Rainbow sprinkles (optional, for decoration)

Instructions

Step 1: Prep the Oven and Cake Base

1. Preheat the oven to 350°F (175°C). Grease a 9x13-inch baking pan with butter or non-stick spray.

2. In a saucepan, melt 2 sticks of butter over medium heat. Once melted, add 1 cup of Guinness beer and bring it to a simmer. Let it cook for 2 minutes, then remove it from heat.

3. Stir in ¾ cup of cocoa powder until smooth. Set this mixture aside to cool slightly.

   
   

Step 2: Mix the Dry Ingredients

4. In a medium-sized bowl, whisk together 2 cups of flour, 1 ½ tsp baking soda, and ½ tsp salt. Set aside.

   
   

Step 3: Prepare the Wet Ingredients

5. In a large mixing bowl, whisk together 2 eggs, ¾ cup granulated sugar, ½ cup brown sugar, and ¾ cup buttermilk until smooth and well combined. Add 1 Tbsp of vanilla extract and mix.

   
   

Step 4: Combine Wet and Dry Mixtures

6. Gradually pour the warm Guinness and cocoa mixture into the buttermilk mixture, stirring gently until just combined.

7. Add the dry ingredients to the wet mixture in batches, stirring until incorporated. Be careful not to overmix; a few small lumps are perfectly fine. Overmixing could cause the cake to sink or become dense.

   
   

Step 5: Bake the Cake

8. Pour the batter into the prepared 9x13 pan and smooth the top.

9. Bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean, or when a digital thermometer reads about 200°F (93°C).

10. Allow the cake to cool completely in the pan.

    
    

Step 6: Make the Irish Cream Buttercream

11. In a stand mixer or large bowl, beat 2 sticks of softened butter using the whisk attachment until light and fluffy.

12. Gradually add 4 cups of powdered sugar, 1 cup at a time, mixing well between each addition.

13. Pour in 3 oz of Irish Cream whiskey and beat until the frosting is smooth and fluffy.

14. Set aside ¼ cup of frosting for piping.

    
    

Step 7: Decorate the Cake

15. Spread the remaining buttercream evenly over the cooled cake using a spatula.

16. To the reserved frosting, add 3 drops of green food coloring and mix well. Transfer to a piping bag.

17. Pipe festive designs, like shamrocks or other St. Patrick’s Day shapes, on top of the cake. For a fun touch, top with rainbow sprinkles.

    

    Guinness Chocolate Cake

    
    
    
    

Tips For Baking Guinness Chocolate Cake

1. Use a Good Quality Guinness:

• The quality of the stout you use can affect the flavor of your cake. Use a good quality Guinness (or another stout beer), as it adds depth to the chocolate flavor and keeps the cake moist.

  
  

2. Don't Skip the Stout Reduction:

• Boiling the Guinness with butter before adding it to the batter helps to concentrate the flavors and make the cake extra moist. Make sure to allow the Guinness-butter mixture to cool slightly before mixing it with the other ingredients.

  
  

3. Use Room Temperature Ingredients:

• Ensure that your butter, eggs, and sour cream (if using) are at room temperature. This helps everything combine smoothly for a better texture.

  
  

4. Don't Overmix the Batter:

• When adding the dry ingredients to the wet ones, mix just until combined. Overmixing can lead to a dense, tough cake.

  
  

5. Grease and Flour the Pan Well:

• To avoid sticking, grease and flour your cake pan (or use parchment paper), especially when using a bundt or springform pan. You can also use cocoa powder to dust the pan after greasing to avoid any flour residue showing on the cake.

  
  

6. Let the Cake Cool:

• Allow the cake to cool completely in the pan for about 20-30 minutes before transferring it to a wire rack. This will help the cake set and prevent it from breaking apart.

Did You Try This Recipe? 

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