Cream together butter and icing sugar.
Add eggs and vanilla extract and mix well.
Sift together flour & baking powder, add to the mixture little by little until well incorporated.
Wait approximately 30 - 60 mins before working with the dough as it will firm up slightly.
Roll the dough between baking paper and put it into the fridge for a few hours to help prevent spreading.
When the dough is a bit firmer, take it out of the fridge and cut into desired shapes (lightly dust with flour if necessary).
Place the cut out cookie dough into a baking tray then put it into the fridge again for another 1-2 hours to help prevent spreading.
Bake cookies at 180° Celsius for approx 10-15 minutes (times may vary slightly depending on your oven).
Let the cookies cool overnight or at least four hours before decorating.