Put softened unsalted butter in a bowl, beat for a while.
Add sugar, and mix them together. Next add beaten egg gradually and whisky well every time.
Sieve the flour into the mixture and make dough. Then put the dough in the fridge for two hours.
Put the dough on a baking paper, roll out about 2-3mm thick. Then cut into desired patterns. Put all cookies in the middle of oven, 170℃ for 12-15 minutes.
Use royal icing and color sugar balls to decorate cookies. I will show you how to make royal icing next time!