Preheat the oven to 180°C. Line 2 x 12 muffin tins with cupcake papers.

Melt the butter into the Coopers Stout in a saucepan over low heat.

Whisk in the cocoa and sugar and take the saucepan off the heat.

Beat the sour cream with the eggs and vanilla in a separate bowl until combined, than add to the beer mixture.

Whisk in the flour and bicarb until combined.

Spoon the mixture into prepared muffin tins and fill approximately ¾ full and bake for 18-20 minutes, or until a toothpick comes out clean.

Allow the cupcakes to cool slightly in their tin before turning out onto a wire rack.

Heat cream up into the microwave until warm (not boiling) and then add finely chopped chocolate, stirring until melted and combined.

Add in the butter and rum and stir until combined. Let the ganache cool until thick and spreadable.

Cream the butter and icing sugar together until well mixed.

Add the cream cheese in cubes slowly until incorporated.

Add in coffee liqueur. Continue mixing for 5 minutes until the icing is light and fluffy.

Take a small, sharp knife and cut a cone shaped piece out of the centre of each cupcake.

Put the cooled rum ganache into a sandwich bag, cut off the tip of a corner, and use it to carefully fill each cupcake with the ganache.

Spoon icing into a piping bag and pipe swirls onto the cooled cupcakes.

Decorate with shavings of dark chocolate if you so desire!