Muffins: Grease a 12-cup muffin tray well and dust with flour. Preheat the oven to 180 degrees C.
Beat the butter with a hand mixer until very fluffy. Gradually stir in the sugar and vanilla sugar then mix well. Stir in the eggs one by one while stirring well after each egg. Then stir in the milk.
Mix flour, baking powder and cocoa then fold in to the mixture with a dough scraper. Finally fold in the chocolate.
Spoon the dough into the prepared muffin tray and bake in the preheated oven for about 20-25 minutes. Use a toothpick to test if the muffins are done in the middle.
Allow the muffins to cool for 10 minutes in the tray then carefully transfer them to a wire rack. Put 2 chocolate drops into the still-warm muffins for eyes then cool completely.
Decoration: Mix the icing sugar with lemon juice to a thick icing. Colour with a few drops of red food colouring.
Cover half of the muffins with the red icing for the body then make a line with the grated chocolate down the middle and use chocolate drops or Smarties for the spots. Cover only a couple of muffins at a time with the icing before decorating with Smarties/chocolate chips as it sets quickly.
Allow the icing to dry and then hand them out to the laughing children.