Line a baking sheet with a silicone mat or parchment paper see note 2
Preheat the oven to 350°F /180°C (160°C fan)
Use a hand held beater or whisk to beat the butter and powdered (icing) sugar for about 2 minutes until light and creamy.
Mix in the vanilla extract.
Add all purpose flour, unsweetened coconut baking powder and salt
Beat until just combined to form a soft dough.
Scoop out equal portions of the dough onto the lined baking sheet
Roll and flatten into ¼ inch (6mm) thick round disks.
Topping (optional)
Top with a sprinkling of coconut on the surface of each flattened cookie.
Bake until golden brown for 15 minutes on the middle shelf of your oven. See note 3
Remove from the oven but leave the cookies on the baking sheet for 5 minutes before transferring to a cooling rack . The cookies will be soft when removed from the oven, but will crisp as they cool.