Pre-heat oven 190C(170 fan)/375F/Gas 5
Cream butter and caster together until light and fluffy (if you have a mixer use it :-)
Add the beaten egg slowly, careful it doesn't curdle if it does add a couple of spoons of flour, whisk well - add the vanilla and whisk
Finally fold in the flour with a wooden spoon, followed by the chocolate chunks - mix well
Half fill the cases with the cake batter and bake for 15-20 mins until golden & firm to touch keep your eye on them.
Remove from the oven and leave to cool
Make the Butter Icing by creaming the butter and icing sugar until smooth, add a drop of milk until you have the desired consistency (again use an electric mixer if you have one
Pipe on top of the cooled cupcakes and decorate however you like …… Enjoy!
I used chocolate chips and 1/2 a mini Cookie & a dusting of Icing Sugar