Preheat the oven to 180˚C (160˚C for fan assisted ovens)/ Gas Mark 4. Line the bun or muffin trays with the cupcake cases.
Mix the eggs, oil, water and cake mix gently together and whisk (by hand or electric mixer) for 2-3 minutes until smooth and creamy.
Pour the cake mixture evenly between the cupcake cases.
Bake in the centre of the oven for around 40 minutes or until or until a skewer inserted into the centre of the loaves come out clean, then cool on a wire rack. Allow to cool completely.in the oven for 14-16 minutes, or until a skewer inserted into the centre of one of the cupcakes comes out clean. Leave in the trays for 5 minutes then transfer to a wire rack and leave to cool.
Mix the vanilla icing with enough of the green food colouring to give the icing a deep Christmas-green colour. Spoon into a piping bag fitted with a star nozzle. Pipe the icing onto the cupcakes, working from the outside of each cake in a spiral and lifting the nozzle at the centre to create a peak.
Sprinkle all the iced cupcakes with half the silver shimmer sugar and chill in the fridge for 20 minutes.
Arrange the cupcakes in a Christmas wreath shape on the board and top with all the edible decorations. Sprinkle over the rest of the shimmer sugar and add a red ribbon bow at the base of the wreath.