Guinness mug cake | Sainsbury`s Magazine

Ingredients

• 2 tbsp soft butter
• 40g dark chocolate, broken into pieces
• 1 medium egg
• 3 tbsp Guinness or other stout
• 3 tbsp dark brown soft sugar
• 4 tbsp self-raising flour
• 3 tbsp icing sugar
• 1 tbsp full-fat cream cheese
• ½ tbsp white edible sprinkles