Guinness Chocolate Sheet Cake with Cream Cheese Frosting

This dark chocolate Guinness sheet cake is baked in a 9-by-13-inch pan and finished with cream cheese frosting. The batter combines cocoa, stout, sour cream, and vanilla for a dark chocolate flavor in every slice. Cool the cake completely before frosting.

Why Make This Dark Chocolate Guinness Sheet Cake

A single rectangular pan makes this cake straightforward to portion and serve. Guinness is warmed with cocoa before it is mixed into the batter, and the cream cheese frosting adds a tangy finish. Use a nonalcoholic stout if you prefer, noting that flavor will vary.

Ingredients

• 1 cup Guinness beer
• 1 cup unsweetened cocoa powder
• 2 cups all-purpose flour
• 2 cups granulated sugar
• 1/2 cup unsalted butter
• 1 teaspoon baking powder
• 1/2 teaspoon baking soda
• 1/2 teaspoon salt
• 2 large eggs
• 1 cup sour cream
• 1 teaspoon vanilla extract
• 8 oz cream cheese
• 4 cups powdered sugar
• 1/4 cup heavy cream

How to Make Guinness Chocolate Cake

1. Heat the oven to 350°F (175°C). Grease and flour a 9-by-13-inch baking pan.
2. In a saucepan over medium heat, warm the Guinness and cocoa powder, stirring until smooth. Remove from the heat and let the mixture cool slightly.
3. In a large bowl, whisk together the flour, sugar, baking powder, baking soda, and salt.
4. In a separate bowl, beat the butter, eggs, sour cream, and vanilla until combined.
5. Add the wet mixture to the dry ingredients and mix just until combined. Stir in the Guinness-cocoa mixture.
6. Pour the batter into the prepared pan and bake for 30–35 minutes. Check the center with a toothpick; it should come out without wet batter.
7. Cool the cake completely. Beat the cream cheese until smooth, then gradually mix in the powdered sugar. Add the heavy cream a little at a time until the frosting is spreadable.
8. Spread the frosting over the cooled cake. Refrigerate until serving.

Serving Suggestions

Cut the chilled cake into squares and let portions sit briefly at room temperature before serving. Cocoa or chocolate shavings make a simple garnish. Serve with coffee or milk. A slice of this dark chocolate cake pairs well with either drink.

Storage

Because the cake has cream cheese frosting, cover and refrigerate it for up to 4 days. Freeze wrapped slices for up to 2 months and thaw in the refrigerator.

Tips for a Moist Cake

• Let the warm stout-cocoa mixture cool slightly before adding it to the batter.
• Mix the flour in just until combined.
• Begin checking the cake near 30 minutes, since pan and oven differences affect timing.
• Cool the cake completely before frosting.
• Add cream to the frosting gradually so it does not become too loose.

Variations

Use a nonalcoholic stout for a similar malt note, though flavor may differ. Chocolate ganache can replace the cream cheese frosting. Add a little espresso powder to the batter if you want a stronger coffee note. For more baking ideas, see Guinness chocolate cake with brown butter frosting. For related guidance, read King Arthur Baking’s cake guide.

Frequently Asked Questions

Can I use another stout?
Yes. Another stout will change the flavor slightly. A nonalcoholic stout is also an option.

Can I make this cake ahead?
Yes. Bake and cool the cake, cover it, and refrigerate. Frost it after cooling, then keep the finished cake refrigerated.

How do I know when the cake is done?
A toothpick inserted into the center should come out without wet batter. Avoid overbaking, which can dry the cake.

Can I freeze it?
Yes. Wrap cooled, frosted slices well and freeze for up to 2 months. Thaw in the refrigerator.

Dark Chocolate Guinness Cake

Print Recipe

A rich and moist cake combining dark chocolate and Guinness, topped with a smooth cream cheese frosting, perfect for any occasion.

• Author: Amelia
• Prep Time: 15 minutes
• Cook Time: 35 minutes
• Total Time: 50 minutes
• Yield: 12 servings
• Category: Dessert
• Method: Baking
• Cuisine: Irish
• Diet: Vegetarian

Ingredients

• 1 cup Guinness beer
• 1 cup unsweetened cocoa powder
• 2 cups all-purpose flour
• 2 cups granulated sugar
• 1/2 cup unsalted butter
• 1 teaspoon baking powder
• 1/2 teaspoon baking soda
• 1/2 teaspoon salt
• 2 large eggs
• 1 cup sour cream
• 1 teaspoon vanilla extract
• 8 oz cream cheese
• 4 cups powdered sugar
• 1/4 cup heavy cream

Instructions

1. Preheat the oven to 350°F (175°C). Grease and flour a 9×13 inch baking pan.
2. Combine the Guinness and cocoa powder in a medium saucepan over medium heat until melted and smooth.
3. Mix together the flour, sugar, baking powder, baking soda, and salt in a large bowl.
4. Beat the butter, eggs, sour cream, and vanilla extract in another bowl.
5. Combine the wet and dry ingredients, then add the Guinness mixture and mix until combined.
6. Pour the batter into the prepared pan and bake for 30-35 minutes or until a toothpick inserted comes out clean.
7. Beat the cream cheese until smooth for frosting, then gradually add powdered sugar and heavy cream until desired consistency is reached.
8. Frost the cooled cake with the cream cheese frosting and serve.

Notes

Use room-temperature eggs and butter for better mixing. Let the cake cool completely before frosting. It pairs well with coffee or milk.