Ingredients:

  • 1 cup (237 ml) stout beer (Guinness recommended)
  • 1 cup (237 ml) unsalted butter, cut into cubes
  • 3/4 cup (60g) unsweetened cocoa powder
  • 2 cups (400g) granulated sugar
  • 1 1/2 cups (192g) all-purpose flour
  • 1 1/2 teaspoons baking soda
  • 3/4 teaspoon baking powder
  • 3/4 teaspoon salt
  • 2 large eggs
  • 1/2 cup (118 ml) sour cream
  • 1 teaspoon vanilla extract
  • 1 cup (200g) granulated sugar
  • 1/4 cup (60 ml) water
  • 1/2 cup (118 ml) heavy cream, warmed
  • 4 tablespoons (56g) unsalted butter, softened
  • 1 teaspoon sea salt, or to taste
  • 1 cup (226g) unsalted butter, softened
  • 3 cups (360g) powdered sugar
  • 2 tablespoons milk, or as needed for consistency
  • 1 teaspoon vanilla extract

Instructions:

  1. Grease and flour two 9-inch round cake pans, line the bottoms with parchment paper circles.
  2. Combine stout and butter in a saucepan. Heat over medium heat until butter is melted. Whisk in cocoa powder until smooth.
  3. In a large bowl, whisk together sugar, flour, baking soda, baking powder, and salt.
  4. Pour the stout chocolate mixture into the dry ingredients and whisk until just combined.
  5. Add eggs, sour cream, and vanilla extract. Mix until smooth.
  6. Divide the batter evenly between the prepared cake pans.
  7. Bake at 350°F (175°C) for 35-45 minutes, or until a toothpick inserted into the center comes out clean.
  8. Let the cakes cool in the pans for 10 minutes, then invert them onto a wire rack to cool completely.
  9. Combine sugar and water in a saucepan. Cook over medium heat, swirling the pan occasionally, until amber in color.
  10. Carefully pour in the warm heavy cream, stirring constantly. Add the softened butter and sea salt. Stir until smooth. Let cool completely.
  11. Beat softened butter in a stand mixer until light and fluffy.
  12. Gradually add powdered sugar, beating until smooth.
  13. Add cooled caramel, milk, and vanilla extract. Beat until light and fluffy.
  14. Level the cake layers with a serrated knife if needed. Place one cake layer on a cake stand or serving plate. Frost with a generous layer of buttercream. Top with the second cake layer. Frost the entire cake with the remaining buttercream.
  15. Chill the cake for 30 minutes to help the buttercream set (optional).
  16. Slice and serve the dark chocolate stout birthday cake for him.