Preheat oven to 350°F
Line baking sheets with parchment paper.
Cream the butter and sugars together in a mixer for 3 mins.
Add the egg and vanilla to combine.
Add the dry ingredients and mix until the dough is combined.
Weigh out 2.5 ounces of dough and roll into balls.
Roll each ball into the extra sugar.
Bake for approx 12 mins. (Check at 10)-they should not be brown and will continue to bake as they cool on the hot sheet.