In large bowl, cream together butter and sugar.
Mix in egg and vanilla.
Sift together flour, salt and baking powder. Add to the wet mix.
Bring dough together.
Shape into a ball and cover with cling film.
Refrigerate and rest the dough for at least 4 hours.
Roll out dough on floured surface until uniform thickness.
Cut out shapes desired and place on baking tray lined with parchment paper.
Bake at 170C fan for 10 - 12 minutes until golden brown.
Remove from tray and let cool on wire rack. Cool completely before icing.