In our attempts at making semifreddo, we had little trouble arriving at a very good flavor. What did give us trouble was the structure of the dessert. It either collapsed and lost its volume or stood up too high and airy when we incorporated all of the ingredients. We suspected that the solution to this problem resided in the meringue, which is a crucial component of the dessert.
Our ideal version of semifreddo, which is something of a cross between a custard and ice cream, features a light vanilla mousse speckled with crushed amaretti cookies and nuts and frozen in a loaf-shaped mold, served in thick slices with a pot of bittersweet chocolate sauce for drizzling. Touched by the warm sauce, the semifreddo immediately begins to melt, blurring the line between cool, airy cream and smooth, rich chocolate.
We started with a cooked, or Italian, meringue, in which a hot sugar syrup is poured into the egg whites as they are beaten. Because the syrup cooks the whites, the meringue becomes more stable and, we hoped, better equipped to stand up to the addition of other ingredients. This did in fact prove to be the case, and so we went on to make several different versions of the dessert as well as a bittersweet chocolate sauce to pour over it.