Devil's food cupcakes

A couple of weeks ago, I went to stay with Lady Pink and Lord Fisherman. Since I was brought up never to arrive empty handed, I thought a home-baked gift would be in order.
 

My local Sainsbury's sells these rather nice gift boxes, which make the whole transporting and giving of cupcakes that little bit easier.

The recipe (below) is a modernised and metricated (is that a word?) version of a 1920s recipe. I originally found the recipe online sometime ago, but cannot find any longer. They were iced with chocolate fudge icing from Mr Oliver Peyton, using an icing gun supplied by the Mission Doctor as she headed off. It is my new favourite baking thing. Pretty icing swirls, minimal mess, and very quick.

Recipe
In three parts.

Ingredients for each part are listed under each part.  

Part One
220g dark brown sugar
115g butter
3 egg yolks
1/2 teaspoon bicarbonate of soda

Cream the sugar, butter and the soda together. Beat in the egg yolks. Set aside. 


Part Two
220g dark brown sugar
240ml milk (the original recipe specifies sweet milk, just so you know)
100g dark chocolate (here the original said 2/3 cup grated chocolate. I approximated)

Put the sugar, chocolate and half of the milk in a saucepan, set over a medium heat and bring to the boil. Take from the heat and add the rest of the milk.

Mix Part One and Part Two together and set aside.  

Part Three
255g plain flour
1/4 teaspoon salt
1 teaspoon baking powder

Sift the flour, baking powder and salt together three times.

Add Part Three to Part One and Part Two. Mix well.

Bake at 160C for 20 minutes or until well risen and a toothpick inserted comes out clean. (The original recipe just said "bake in a medium oven")

Leave to cool, then ice. And eat.