===== Ingredients =====

==== Cake ====

  * 1 cup Guinness stout
  * 10 tablespoons (1 stick plus 2 tablespoons) unsalted butter
  * 3/4 cup unsweetened cocoa
  * 2 cups superfine sugar
  * 3/4 cup sour cream
  * 2 large eggs
  * 1 tablespoon vanilla extract
  * 2 cups all-purpose flour
  * 2 1/2 teaspoons baking soda

==== Icing ====
  * 1 1/4 cups confectioners' sugar
  * 8 ounces cream cheese at room temperature
  * 1/2 cup heavy cream

===== Procedure =====

==== Cake ====

  - Preheat oven to 350 degrees.
  - Butter a 9-inch springform pan and line with parchment paper.
  - In a large saucepan, combine Guinness and butter.
  - Place over medium-low heat until butter melts, then remove from heat.
  - Add cocoa and superfine sugar, and whisk to blend.
  - In a small bowl, combine sour cream, eggs and vanilla; mix well.
  - Add to Guinness mixture.
  - Add flour and baking soda, and whisk again until smooth.
  - Pour into buttered pan, and bake until risen and firm, 45 minutes to one hour.
  - Place pan on a wire rack and cool completely in pan.

==== Icing ====

  - Using a food processor or by hand, mix confectioners' sugar to break up lumps.
  - Add cream cheese and blend until smooth.
  - Add heavy cream, and mix until smooth and spreadable.

Remove cake from pan and place on a platter or cake stand. Ice top of cake only, so that it resembles a frothy pint of Guinness.