• Butter, for the pan

• 1 cup (240 ml) Guinness stout

• 10 tablespoons (1 stick plus 2 tablespoons) unsalted butter

• ¾ cup (60 g) unsweetened cocoa powder

• 2 cups (400 g) superfine sugar

• ¾ cup (180 ml) sour cream

• 2 large eggs

• 1 tablespoon vanilla extract

• 2 cups (240 g) all-purpose flour

• 2½ teaspoons baking soda

For the Topping:

• 1¼ cups (150 g) confectioners’ sugar

• 8 ounces (225 g) of cream cheese, at room temperature

• ½ cup (120 ml) heavy cream