Chocolate Guinness Cupcakes

My first Guinness recipe was a bit of a disaster, but sin scéal eile (Gaelic for "that's another story").  
So, maybe I do have some Irish luck, after all.  Second time is a charm? These cupcakes bake up like a bit of Irish magic.  Light, airy, and moist - magically delicious!  

Chocolate Guinness Cupcakes

1 cup all purpose flour, sifted
1/2 cup brown sugar
1/2 cup granulated sugar
1 tsp baking soda
1/4 tsp salt
1 egg
1/4 cup buttermilk
1/2 cup unsalted butter
3/4 cup Guinness or stout beer
1/2 cup cocoa 

Melt butter in a small saucepan, adding cocoa and Guinness, stirring until well combined. Remove from heat and let cool for 5 minutes.
Combine flour, baking soda, salt, and sugars in a medium bowl.  Set aside.
Combine egg and buttermilk in a medium sized bowl.  Add cooled chocolate mixture.  Mix well.  
Make a well in centre, and add flour mixture, stirring until well combined.
Batter will be runny, that's ok - don't worry! 
Pour into 12 cupcake liners and bake at 375 degrees for about 20 minutes or until toothpick inserted in the centre of the middle cupcake comes out clean.

Guinness icing
1/4 unsalted butter, softened
1 cup icing sugar
1/4 cup cocoa
1/3 cup Guinness
1/2 tsp vanilla

Cream butter with icing sugar, add in cocoa. 
Add beer and vanilla, mix until the right consistency, adding in more icing sugar for a thicker icing, and more beer if too thick.