Mix the flour, bicarbonate of soda, cornflour and salt in a bowl. This is your dry mix. Then in another bowl mix the melted butter with the sugar for a minute before adding in the egg and vanilla extract. This is your wet mix. Pour the wet mix into the dry mix and stir until combined. Finally stir in the chocolate and orange zest. This should form a dough. Roll it into a sausage approx. 4cm in diameter. Wrap in cling film and refrigerate for at least 2 hours. I sometimes find it easier to spoon it out onto the clingfilm into a rough sausage shape, then wrap the clingfilm around it before giving it a quick roll in the clingfilm.
Once the cookie dough has chilled, pre-heat your oven to 160c.
Take the cookie dough out of the fridge and slice into 25-30 rounds and place onto non-stick baking sheets. Make sure there’s room between the cookies as they will spread during cooking. I used four baking sheets and baked the cookies in two batches.
Place the cookies in the oven and bake for 7 minutes. You can bake them for a couple of minutes longer if you like your cookies crispier.
Take out of the oven and leave to cool for a few minutes before gently removing from the tray with a spatula and leaving to cool completely on a cooling wrack.
Notes
Tip These cookies should keep for up to a week wrapped and placed in a sealed container.Nutritional info is estimated per cookie