As made by Insatiable Thirst with thanks to Doggy Style for the introduction!
Source: http://www.nigella.com/recipes/view/chocolate-guinness-cake-3086
for the cake
* 250 ml / 1 cup Guinness
* 250 grams unsalted butter
* 75 grams / 3/4 cup cocoa powder
* 400 grams / 2 cups caster sugar
* 142 ml/ 3/4 cup sour cream
* 2 large eggs
* 1 tablespoon vanilla extract
* 275 grams / 2 cups plain flour
* 2 ½ teaspoons bicarbonate of soda
for the topping
* 300 grams / 8 oz cream cheese
* 150 grams / 1 1/4 cup icing sugar
* 125 ml / 1/2 cup double cream (or whipping cream)
1. Preheat the oven to gas mark 4/180°C/350ºF, and butter and line a 23cm / 9 inch springform tin.
2. Pour the Guinness into a large wide saucepan, add the butter - in spoons or slices - and heat until the butter's melted, at which time you should whisk in the cocoa and sugar. Beat the sour cream with the eggs and vanilla and then pour into the brown, buttery, beery pan and finally whisk in the flour and bicarb.
3. Pour the cake batter into the greased and lined tin and bake for 45 minutes to an hour. Leave to cool completely in the tin on a cooling rack, as it is quite a damp cake.
4. When the cake's cold, sit it on a flat platter or cake stand and get on with the icing. Lightly whip the cream cheese until smooth, sieve over the icing sugar and then beat them both together. Or do this in a processor, putting the unsieved icing sugar in first and blitz to remove lumps before adding the cheese.
5. Add the cream and beat again until it makes a spreadable consistency. Ice the top of the black cake so that it resembles the frothy top of the famous pint.
My notes: cups, Tablespoons and teaspoons are the American sizes.
I have read a suggestion to let the beer go flat but I haven't managed to work that into the cooking timetable yet - advanced preparation, what? The point of having flat beer is that there's no foam to go to waste.
I use regular sugar instead of caster sugar cos I'm lazy like that plus reduce the sugar to 1 1/2 cups with no ill effects. I think 1 cup of sugar might be going too far though (based on comments from when I doubled the recipe and only put in 2 cups of sugar). Also, I use yogurt instead of sour cream as that's what I've usually got in the fridge.
I mix everything for the batter in the one pot i.e. i heat the beer and butter. Then take it off the heat and mix everything else in.
I have added 1 Tbsp chili powder to the batter for a slight kick; have also added um, 1 1/2 Tbsp (eyeballed) but that was too spicy for some - although weirdly unnoticeable to others!
I omit the double cream/whipping cream for the topping as I found it too runny if I added the cream. You can also add in 1 Tbsp of Bailey's - I did it once but don't like Bailey's so didn't do *that* again.
My technique for the topping is dump the whole tub of cream cheese into a bowl, add in some of the icing sugar (could probably get away with 1 cup of icing sugar), mix with fork. The topping will become softer the longer you mix. Add in rest of icing sugar if you don't forget and continue to mix until you think it's a spreadable consistency. Plop onto cake and spread. Yes, lots of love goes into this!!
As always, I suggest following the recipe as printed the very first time to use as a baseline then making the recipe your own.