Preheat the oven to 175°C (350°F) and line a baking tray with parchment paper.
Cream butter and sugar together until smooth and fluffy.
Add egg and vanilla extract, then mix well.
Combine flour and baking powder, then gradually add to the mixture to form a dough.
Roll out the dough and cut into desired cookie shapes.
Bake for 8–10 minutes until the edges are lightly golden.
Let cookies cool completely.
Prepare royal icing, decorate the cookies, and allow icing to set before serving.