Add melted burger to a bowl. Then add brown sugar and granulated sugar. Mix. Then add the egg and vanilla and mix until thick and smooth. Then add the flour, salt and bicarbonate of soda to a sifter and sift it into the mix. Then add the chocolate chips and mix. Now put the mix into the fridge for at least 30mins. After, scoop up 1-2 tbsp of the dough and place it on a baking tray. Bake for 10mins on 180°C.