Chocolate Guinness Cake with Irish Buttercream Frosting

caramel sauce drizzled over guinness chocolate cake

Chocolate Guinness Cake with Irish Buttercream Frosting

A slice of Guinness Chocolate Cake with smooth Irish cream frosting is exactly what any celebration needs… or any day you need a pick-me-up!

Author: Donna Elick

Servings: large squares or 16 smaller squares (about 1 piece per serving)

Prep Time15

Cook Time40

Total Time55

Ingredients

Chocolate Guinness Cake

1 cup Guinness beer, room temperature
1 cup unsalted butter, cut into pieces
3/4 cup cocoa powder
2 cups granulated sugar
3/4 cup sour cream, room temperature
2 large eggs, room temperature
1 tablespoon pure vanilla extract
2 cups all-purpose flour
2 1/2 teaspoons baking soda
1/2 teaspoon kosher salt

Irish Buttercream Frosting

1 cup unsalted butter, softened
4 cups powdered sugar, sifted
2 to 4 tablespoons Irish cream liqueur such as Baileys
1 teaspoon pure vanilla extract

Optional Toppings

Caramel sauce
Chocolate shavings
Sprinkles

Instructions

PREPARE OVEN: Preheat the oven to 350°F. Grease a 9 by 9-inch baking pan or line with parchment paper.
HEAT STOUT: In a medium saucepan over medium heat, add 1 cup Guinness beer, room temperature and 1 cup unsalted butter, cut into pieces. Heat until the butter is fully melted.
ADD COCOA: Whisk in 3/4 cup cocoa powder until smooth. Remove from heat and let cool slightly.
MIX DRY INGREDIENTS: In a large mixing bowl, whisk together 2 cups all-purpose flour, 2 cups granulated sugar, 2 1/2 teaspoons baking soda, and 1/2 teaspoon kosher salt.
MIX WET INGREDIENTS: In a separate bowl, whisk together 3/4 cup sour cream, room temperature, 2 large eggs, room temperature, and 1 tablespoon pure vanilla extract until smooth.
COMBINE BATTER: Slowly whisk the Guinness mixture into the sour cream mixture. Pour the wet ingredients into the dry ingredients and stir until smooth and fully combined.
BAKE: Pour the batter into the prepared pan and spread evenly. Bake for 35 to 40 minutes, until a toothpick inserted in the center comes out clean.
COOL: Remove the cake from the oven and let cool completely in the pan.
MAKE FROSTING: In a large mixing bowl, beat 1 cup unsalted butter, softened until creamy. Gradually add 4 cups powdered sugar, sifted, mixing on low speed until combined.
FLAVOR FROSTING: Add 2 to 4 tablespoons Irish cream liqueur and 1 teaspoon pure vanilla extract. Beat on medium speed until light and fluffy. Add additional Irish cream, 1 tablespoon at a time, until desired flavor and consistency are reached.
FROST CAKE: Spread the buttercream evenly over the cooled cake.
SERVE: Add optional toppings if desired. Slice and serve.

Notes

Pan Options: This cake can also be baked in a 9 by 13-inch pan. Bake for 25 to 30 minutes and check for doneness.

Make-Ahead: The cake can be baked 1 day ahead and frosted before serving.

Storage: Store covered in the refrigerator for up to 3 to 4 days. Bring to room temperature before serving for best flavor and texture.

Freezing: Freeze the unfrosted cake for up to 2 months. Thaw overnight in the refrigerator before frosting.

No Alcohol Option: Substitute the Guinness with an equal amount of strong brewed coffee. Omit the Irish cream liqueur and use milk or cream in the frosting instead.

Ingredient Tip: Room-temperature ingredients are key for a smooth batter and even bake.

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