Transfer the mousse to a piping bag. Pipe a tablespoon of the mousse in each of the chocolate moulds. Spread the mousse up the side of the chocolate mould. Add a tsp of the salted caramel into the centre. Carefully pipe the mousse on top of the caramel. Using a pallet knife, level out the top of the mousse. Leave for an hour and allow to set. If not serving within the hour, place in the fridge but allow to come to room temperature before serving.