Beat butter in an electric mixer until smooth, add Chelsea Caster Sugar and beat until light and fluffy. Add eggs and mix well. Add the vanilla, flour and milk. Beat until smooth.
Place individual paper baking cups in a cupcake tin, spoon in mixture until they are about 2/3 full - you should get 24 cupcakes (don't overfill as they will 'peak'). Bake in the oven at 190°C for 20 minutes or until golden. While cupcakes are cooling on a wire rack, prepare icing.
Measure Chelsea Chocolate Icing into a bowl, add butter and hot water, mix until smooth. Icing should spread easily; if too thick add a little more hot water to allow it to spread easily. To decorate: Spread chocolate icing thickly on to cooled cupcakes. Arrange chocolate pieces around the outer edges, pushing gently into the icing. Finish by placing mini eggs in the centres.