A clever idea: hollow bars.

The cooled mould is filled with liquid chocolate, but is then turned, so that some of the chocolate flows out again and only the outer, already solidified, layer along the walls of the mould remains. The cooled and rigid chocolate case is upturned again and the filling is inserted and evenly distributed by vibrating it. In the third step, the future base of the chocolate bar is now poured over. Surplus chocolate mass is removed with a scraper and the base-coat is smoothed.