Thoroughly mix the butter, sugar and vanilla paste, stir in the egg. Combine the flour and baking powder, mix in. Shape the dough into a ball, flatten a little, cover and leave to chill for approx. 30 mins.
To roll out the dough
Roll out the dough approx. 2 mm thick between two sheets of baking paper, cut out circles approx. 6 cm in diameter. Place the circles on 4 trays lined with baking paper.
To bake each tray
Approx. 7 mins. in the centre of an oven preheated to 200°C. Remove from the oven, leave to cool on a rack, repeat the process with the remaining trays.
Combine the egg whites with enough icing sugar to make a thick icing. Stir in the edible silver glitter. Spread on top of the biscuits, decorate with sugar decorations.