Sacher Torte (Viennese Dark Chocolate Apricot Cake)
This Viennese chocolate cake, heavy on dark chocolate and butter, is split and spread with apricot jam, then covered all over with a glaze of chocolate melted into cream. Pour the glaze in one go; that is what leaves a mirror-smooth top. Once it sets, slice with a knife dipped in hot water so the thin line of jam shows cleanly through the dark crumb.