Line a 12 hole muffin tin with 9 paper muffin cases and preheat the oven to 180C/gas 4
Cream the butter and sugar together in a large bowl using an electric whisk. Add in the eggs and vanilla and beat together.
Fold in the flour using a large metal spoon. Add a little single cream or milk here until you have a dropping consistency. Fold in your sprinkles. Be careful not to over mix or the colour at run.
Spoon the mixture into your lined muffin tin so each paper case is approximately half full.
Bake in the oven for about 15 minutes or until golden brown. Set aside and leave to cool completely before icing.
For the butter icing, beat the butter in a large bowl until really soft. Add half of the icing sugar and mix well.
Add the remaining flour and your cream of milk and beat until smooth.
Using a knife or spatula cover each cupcake with icing and top with sprinkles.