Sift the flour, baking soda, baking powder and salt, if using. Set aside.
Preferably in a stand mixer so that the volume of the dough is easier to handle, beat the butter and sugars until pale and fluffy, 3 to 4 minutes. You could use also a hand mixer.
Add the eggs and vanilla and beat again till combined.
Now slowly mix in the flour mixture, until just combined. Do not over-mix.
Finally, mix in the chocolate chips and if using a mixer, do this on low speed so that they don't break or blend into the dough.
Cover the bowl with clingfilm and chill for 3 hours up to 24 hours*.
When ready to bake, preheat the oven to 175 C and lightly grease a baking mat or line it with a silicone sheet.
Roll the dough into equal sized balls, about 2 tbsps each. These will be a little larger than your average cookie so that they hold all the chocolate. Place at least two inches apart on the baking tray.
Bake 10 to 12 minutes for soft, squidgy cookies and up to 15 for crunchy cookies. For flatter cookies, lightly flatten the dough balls before baking. Please read the post above for more details on texture.
Allow the cookies to cool for a few minute before face planting into them :D