Place the butter in a bowl, beat in the sugar and salt. Add the egg and beat until the mixture becomes lighter in colour. Combine the flour and cocoa, add to the bowl, mix to create a dough – do not knead. Shape the dough into 2 rolls of equal size, cut each roll into 12 equal pieces and shape into balls. Place the balls on two trays lined with baking paper, flatten slightly (approx. 7 cm in diameter).
Into each of the raw cookies, press 2 pretzels for antlers, 2 sugar eyes and 1 brown Smartie for the nose.
Bake each batch for approx. 11 mins. in the centre of an oven preheated to 180°C. Remove from the oven, slide the cookies onto a cooling rack and leave to cool.