Beat the butter and sugar: In a large bowl, beat the butter on medium speed for 3 minutes until light and creamy. Add sugar and beat for another 2 minutes.
Add the egg and vanilla extract and beat for 1 minute to combine
Sift in the dry ingredients: Sift the flour, baking powder and salt (if using) into the mixture.
Form a soft dough: Combine to form a soft dough. Add an additional 2 Tablespoons flour if you feel that the dough is too soft to handle.
Wrap dough in plastic wrap: Wrap the dough tightly in plastic wrap (cling wrap) and refrigerate for 30 minutes.
Divide the dough in 4 portions. see note 2
Roll out the dough: Roll out the dough on a floured surface. When rolled out, the dough should be about ⅛ inch (4mm) thick. See note 3
Preheat the oven: Preheat the oven to 350°F/180°C (160°C fan).
Line a baking sheet with parchment/baking paper. See note 4
Cut/Shape the dough: Dip the cookie cutter in flour. Work from the center of the rolled-out dough to the edges, cutting shapes close to one another to prevent extra scraps and extra re-rolling.
Transfer the dough to the lined baking sheet see note 5
Bake the cookies for between 10 to 12 minutes see note 6
The cookies are baked when the edges are set and lightly browned. The top centers can look and feel soft when removing from the oven. See note 7
Remove from the oven and leave the cookies on the baking tray for 5 minutes. Then transfer to a wire rack to cool completely before decorating.