Pre-heat the oven to 175ºC (350℉).
Cream the butter and icing sugar together until fluffy.
Combine the flour and vanilla sugar and mix with the butter/sugar until a fairly dough forms.
Roll the dough out between two sheets of baking paper until it is quite thin.
When ready, transfer to your baking tin (see note 2) and push the dough up the sides of your pan, making sure the dough is fairly even.
Bake in the oven for around 18-20 minutes. The crust will have started to brown on the edges, but the middle will still be pale.
Remove from the oven and push the crust down down with the back of a spoon or glass (it will have bubbled up a little) and up towards the sides again. Leave to cool completely.