Instructions

1. Pre-heat oven to 180°C / 160°C fan / gas 4 and line a 20cm (8inch) round cake tin with parchment paper.
2. Pour the Guinness into a large saucepan with the butter. Over a medium heat, heat until the butter has melted.
3. Remove saucepan from heat then whisk in the cocoa powder and sugar.
4. In a small bowl, whisk together sour cream, eggs and vanilla, add this to the saucepan and mix well.
5. Finally, add the flour and baking soda, stir in with a whisk, scraping down the sides of the saucepan with a spatula if needed.
6. Pour the batter into the prepared baking tin then bake in pre-heated oven for 1 hour 10 minutes – 1 hour 20 minutes. Use a skewer to test if it’s done, insert into the centre of the cake, if there is any wet batter on the skewer, continue baking. A few sticky crumbs are fine, though.
7. Once baked, leave to cool completely in the cake tin on a cooling rack. Once completely cool, turn out from the cake tin.
8. For the frosting, beat together the butter and sugar with about 1 tbsp of the cream cheese until it’s smooth and creamy. Add the chilled cream cheese and whisk until frosting is creamy and thick. Finally, whisk in the Baileys and vanilla.
9. Place the sponge on a serving dish then spread the cream cheese frosting over the top.