Mix the flour and baking powder. Mix egg, sugar, oil, eggnog and milk well. Add the flour mixture and stir in briefly. Grease the mini cake tin (10 troughs; each containing 100 ml) and dust with flour. Spread the dough in it. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for 25-30 minutes. Leave to rest for approx. 5 minutes in the baking trays, then remove and allow to cool.
Stir icing sugar and egg white until smooth. If the icing is too thick, stir in 2-3 tablespoons of water. Halve the icing, colour one half green with food colouring. Pour 2-3 tablespoons of each glaze into a piping bag. Coat the muffins with the remaining icing and let them dry. Cut off a small corner of each piping bag. Decorate the muffins with the icing, let them dry