Preheat oven to 170°C.
Place butter and brown sugar in a large bowl or bowl of your stand mixer. Cream together, until pale, about 4 minutes.
Add egg and golden syrup and continue to mix for 2 minutes.
Fold in gingerdoodle mix, until combined. Place in the fridge, covered, to firm up for 30 minutes.
Place white sugar in a bowl. Roll cookie dough into golf ball sized balls and then roll in the sugar.
Place on two lined oven trays, leaving at least 5cm between each cookie. Bake each tray for about 12 minutes, until golden. Cookies will be soft and chewy when set.