Preheat the oven to 175 C. Line a baking tray (or two if you're baking in batches) with silicone baking mats. Set aside.<br></br>

Sift the flour, baking soda, baking powder and salt, if using. Set aside.<br></br>

In a mixing bowl, combine the sugars and orange zest, then rub the mixture with your fingers for a minute to release the orange flavour and moisten the sugars.<br></br>

Add the butter and using a hand mixer, beat until light and fluffy.<br></br>

Add the egg and vanilla and beat again till combined.<br></br>

Now fold in the flour mixture, until just combined. Do not over-mix. Fold in the chopped chocolate making sure it's distributed evenly through the dough. <br></br>

Using a cookie scoop, an ice cream scoop or two large spoons, drop dollops of the dough onto the baking tray, at least two inches apart. Shape them into rounds as best as you can, but we're not aiming for perfection since the dough will be soft and sticky.<br></br>

Bake for 10 until the cookies are lightly browned on the edges and still puffy in the middle, rotating the tray halfway through the baking time to ensure even browning. Very gently, press down on each cookie with the back of a spoon to flatten further and allow them to cool and firm up for about 15 minutes before diving in!<br></br>