Here you should use the fruit pulp left over from the plum juice.   Whip the cream into foam together with a little vanilla sugar. Crush the macaroons.  Take a beautiful glass bowl of appropriate size and layer crushed macaroons (sprinkle the macaroons with a bit of port wine or sherry), plum pulp and whipped cream. Alternatively, you can use serving glasses to arrange the trifle in.  Optionally, garnish the trifle with a splash of blanched, chopped almonds on top before serving.