Cream 140g butter, 140g brown sugar and 110g caster/granulated sugar together Sift in 250g plain flour, 3g baking powder, 4g bicarb and mix Add in 100g (or up to 180g) chocolate chips Divide into 60g cookie dough balls and refrigerate for at least 24 hours Bake at 180c or 160 fan for 12 mins