Preheat oven to 180°C.
Line a standard-size muffin pan with cupcake liners. Place the chopped chocolate and cocoa powder in a medium-sized bowl, pour the hot coffee over the mixture and whisk until smooth. Allow to cool slightly before using.
Meanwhile, whisk together the flour, sugar, salt and baking soda in a separate bowl.
Add the oil, eggs, vinegar and vanilla into the chocolate mixture and mix until smooth. Add the flour mixture to this and beat until smooth.
Divide the batter evenly between the muffin pan cups. Bake until cooked, 17 to 19 minutes. Cool on a wire rack.
To make the icing, beat the butter until pale yellow and fluffy. Sift the cocoa and icing sugar, then add to the butter. Beat until combined and smooth, gradually adding the milk until it reaches your desired consistency.
Recipe reprinted with permission of A Gorgeous Life. To see more recipes, click here.