Preheat your oven to 180 C or 350 F.
Line a cookie sheet with parchment or grease well.
Sift or whisk together flour, baking soda and salt.
Beat together the sugars and butter until creamy and fluffy. This takes around 5 minutes with an electric beater.
Add the egg and vanilla and beat until incorporated.
Add in the flour mixture and beat until dough forms.
Mix in the chocolate chips.
Chill the dough for half an hour (optional)
On a parchment lined, or greased cookie sheet lay down cookie dough balls of roughly 1.5 - 2 cm diameter. Leave around 2 inches space between the cookies.
Bake at 180 C for 18-20 minutes. Turn the sheet (so that what was facing towards front of oven ,goes to the back of the oven and vice versa) after about 10 minutes.
Cool on pan for 5 minutes and then completely on wire rack.