• Preheat oven to 350 F.
• Butter the sides of the spring form pan and line the bottom.
• Pour Guinness into a small sauce pan over medium heat. Add butter and heat until butter is melted.
• Remove from heat and whisk in cocoa powder and sugar. Set aside.
• Combine sour cream, eggs, and vanilla in a large bowl. Beat until combined.
• Add Guinness mixture to sour cream mixture. Whisk to combine.
• Combine flour and baking soda in a large bowl.
• Whisk in flour mixture to wet ingredients. Do not over mix.
• Pour batter into prepared cake pan and bake for 50 minutes to 1 hour or until a toothpick or clean knife come out clean.
• Place on wire rack to cool completely.
• Dust with icing sugar or top with whip cream icing (recipe below).

Whipped Cream Icing

• Place a the bowl of an electric mixer in the fridge for at least 10 minutes.
• Take out the mixing bowl once the bowl is chilled. Add the heavy cream, icing sugar, and vanilla.
• Beat the ingredients in a on low speed, gradually increasing the speed to high.
• Beat until soft peaks form. Do not over-beat or you will end up with a sweet butter.
• Keep unused icing in the fridge.