Cream the butter & sugar together with the molasses, , then add the eggs, one by one, then add all the sieved dry ingredients, and the vanilla, mix this for a minute followed by the melted chocolate. Mix till combined, then roll into 60g balls and press lightly down on a baking parchment on a baking tray. Place into the oven at 200c for 8-10 mins only so they stay goey, place onto wire rack to cool.