For the cupcakes
4 oz. unsalted butter, room temperature
4 fl. oz. Guinness (or any other stout)
8 oz. soft light brown sugar
2 oz. cocoa powder, sifted
3 fl. oz. plain Greek yoghurt
1 tsp. vanilla extract
2 eggs
5 ½ oz. self-raising flour
1 tsp. bicarbonate of soda

For the cream cheese frosting
2 oz. unsalted butter, room temperature
4 oz. cream cheese, chilled
Couple drops vanilla extract (optional)
1 lb. icing sugar, sifted
Green gel food colouring

Decorations
12 gold chocolate coins

1. Preheat oven to 180º Celsius and line a muffin tray with paper muffin(-size) cases.
2. In a small pot over a medium heat, add the butter and Guinness. Melt the butter and stir frequently. Once melted remove from the heat and pour into a mixing bowl.
3. Stir in the sugar and cocoa. 
4. In a separate mixing bowl, gently beat together the yoghurt, vanilla and extra. Add to the chocolate mixture and stir until thoroughly combined. Next sift in together the flour and bicarbonate of soda. Mix, until thoroughly combined scraping the sides and bottom of the bowl as you go.
5. Next, pour or scoop the batter into the cases until about 2/3 full. Bake in the oven for 18-20 minutes or until a toothpick inserted comes out clean.
6. Once baked, leave the tray of cupcakes to cool on a wired rack for about 5 minutes, then remove the cupcakes from the tray and leave to cool completely on the wired rack.
7. Make the frosting by beating the butter in a large mixing bowl (or in a stand mixer fitted with a paddle attachment). Next, add the cream cheese and mix until thoroughly combined. Add in the icing sugar and gently mix. Whisk on a high speed for about 1 minute or until you reach a silky consistency.
8. Cut the bottom of a piping bag the size of a (woman’s) thumb. Place the bag into a long glass to hold it. Gently squeeze the gel down two opposite sides of the piping bag to that it runs down the piping bag. Next add the frosting squeezing it down to the tip. Holding the bag upright, apply pressure to pipe spirals on to each cupcake. Decorate with a gold coin on top.