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A slice of moist Guinness Chocolate Cake with rich chocolate frosting sits on a plate.

Ultimate Guinness Chocolate Cake

This iconic cake uses dark stout beer to create an exceptionally moist, tender, and deeply chocolatey dessert. The Guinness is heated with butter to mellow its bitterness, then combined with natural cocoa and sour cream for a perfect acid-base reaction and rich crumb. It's finished with a silky, not-too-sweet chocolate buttercream for a sophisticated and celebratory treat.
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Prep Time 45 minutes
Cook Time 35 minutes
Total Time 1 hour 20 minutes
Servings: 12
Course: Dessert
Cuisine: American
Calories: 650
Ingredients Equipment Method Notes

Ingredients
  

  • For the Cake: 1 cup 240ml
  • 2 large eggs + 1 large egg yolk, at room temperature
  • 1 tablespoon pure vanilla extract
  • 2 1/2 teaspoons baking soda
  • 3/4 teaspoon fine sea salt
  • For the Frosting: 12 ounces 340g
  • 1 teaspoon pure vanilla extract
  • Pinch of salt

Equipment

  • Two 9-inch round cake pans
  • Parchment paper
  • Medium saucepan
  • Large mixing bowl
  • Whisk
  • Spatula
  • Wire cooling rack
  • Double boiler or microwave-safe bowl
  • Stand mixer with paddle attachment (or hand mixer)
  • Measuring cups and spoons
  • Sifter

Method
 

  1. Preheat oven to 350°F (175°C). Generously butter and flour two 9-inch round cake pans, lining the bottoms with parchment paper.
  2. In a medium saucepan, combine the Guinness and butter. Heat over medium until the butter melts. Remove from heat and whisk in the cocoa powder and granulated sugar until smooth. Transfer to a large mixing bowl and let cool for 10 minutes.
  3. Whisk the sour cream, whole eggs, egg yolk, and vanilla extract into the lukewarm chocolate mixture until well combined.
  4. Sift the flour, baking soda, and salt directly into the bowl with the wet ingredients. Using a spatula, fold the dry ingredients into the wet until just combined and no dry streaks remain. The batter will be thin.
  5. Divide the batter evenly between the prepared pans. Bake for 30-35 minutes, until a toothpick inserted into the center comes out clean.
  6. Cool the cakes in the pans on a wire rack for 15 minutes. Then, invert them onto the racks, peel off the parchment paper, and let them cool completely before frosting.
  7. For the frosting: Melt the chopped chocolate in a double boiler or in short bursts in the microwave, stirring until smooth. Let cool to barely lukewarm.
  8. In a stand mixer fitted with the paddle attachment, beat the softened butter on medium-high speed until pale and fluffy, about 3 minutes.
  9. Reduce speed to low and gradually add the sifted confectioners' sugar. Beat until combined.
  10. Increase speed to medium and add the heavy cream, vanilla extract, and pinch of salt. Beat until light and fluffy, about 2 minutes.
  11. With the mixer on low speed, slowly pour in the cooled, melted chocolate. Beat until the frosting is uniform, smooth, and silky.
  12. Frost the completely cooled cake layers as desired.

Notes

Use only natural (non-alkalized) cocoa powder; Dutch-process will not react properly with the baking soda. Ensure all dairy ingredients (sour cream, eggs, heavy cream) are at room temperature for a smooth, emulsified batter and frosting. The thin batter is normal. Do not over-mix once the flour is added to avoid a tough crumb. The cake can be stored in an airtight container at room temperature for up to 2 days or refrigerated for up to 5 days. Bring to room temperature before serving for best texture and flavor.