Grease baking tray with margarine and dust with little flour.

In a bowl mix icing sugar with margarine until well combined.

Add the egg and vanilla and mix well

Add the flour and baking powder in 2 bunches combining well
Put the mixture in a piping bag and use the large start nozzle to pipe on the baking tray

Bake in a preheat oven, 160° for approximately 15 minutes

Note: after 10 minutes of baking switch off the bottom heat and finish baking with top heat only