Preheat oven to 160 degrees Celsius
Line 2 trays with parchment paper
Whisk the flour, bicarbonate of soda, brown sugar and white sugar together
Place the butter (fridge cold) in a bowl and microwave for 40 seconds and set aside. If it's room temperature butter you may need to adjust the time to about 20-30 seconds
Beat the egg and vanilla essence into the butter and mix into the flour mixture
Mix in the chocolate chips. It will be a soft cookie dough and look almost buttery
Scoop up a level ice-cream scoop of cookie dough and place on the lined cookies tray. Place more chocolate chips on top of each cookie. I only baked 6 cookies on each tray. They need to be spread apart, at least 6cm. I used a 40cm x 30cm tray.
Bake at 160 degrees Celsius for 10 minutes. Turn up the temperature to 180 degrees Celsius and bake for another 3-4 minutes until slightly brown on the edges
Cookies will still be soft when removed from the oven
Cool on a cooling rack