Chocolate Stout Cake

250g soft butter

250ml stout

75g cocoa powder

400g golden caster sugar

150mls sour cream

2 eggs

2 tsp vanilla

270g plain flour, sieved

2 tsp bread soda, sieved

For the icing

200g cream cheese

2 tbsp honey

1 tsp lemon juice and zest 1 lemon

1 tsp vanilla

100g icing sugar