Beat butter and sugar until light and creamy.
Add eggs one at a time beat well after each addition.
Sift dry ingredients together and add with rest of ingredients to the butter mixture.
Fill the hollows of the muffin pan with cupcake holders and spoon batter into them.
Bake in a preheated oven at 180°C for 35 - 45 minutes until done.
Remove, turn out and allow to cool completely.
Prepare icing by beating all the ingredients together until creamy.
Decorate cupcakes with icing and serve.