Place the stout, coffee, raisins and butter into a saucepan and over a medium heat stir until the butter has melted. Remove from the heat and add the Dark chocolate, stir until the chococlate has melted. Set aside to cool.
Sift the flour, baking soda and salt into a bowl and stir to combine with the sugar.
In a separate large bowl whisk together the eggs, sour cream and cocoa vanilla extract. Whisk in the cooled stout mixture.
Add the dry ingredients in 3 lots stiring from the centre until each lot is well combined.
Pour into the pre-prepared bundt tin and bake for 45-50 minutes or until a skewer comes out clean.
Remove from the oven and set aside for 15 minutes before inverting on a cake rack to cool.
Frosting Method:
Place the cream and butter into a medium saucepan and heat until just below boiling. Remove from the heat and add the chocolate stirring constantly until the chocolate has melted and you have a smooth glossy mixture. Allow to cool for 20 minutes before pouring over your cold cake.