Ingredients and Methods
Line a 1Lt loaf pan or plastic container with plastic wrap, leaving plenty overhanging the sides.
Melt chocolate in a heatproof bowl set over a pan of simmering water (don’t let the bowl touch the water). Once the chocolate has melted, remove bowl from the heat and keep the water at a simmer.
Using electric beaters, whisk egg yolks, sugar and amaretto together in a separate heatproof bowl until pale and lightly fluffy. Place the bowl over the pan of simmering water and continue to beat until the mixture doubles in volume and starts to thicken (zabaglione in Italian – or sabayon). Whisk in the melted chocolate, then remove from the heat and allow to cool to room temperature.
In a clean bowl, beat egg whites to soft peaks. In another bowl, whip the cream. Using a spatula, gently fold cream into the cooled chocolate mixture, followed by egg whites. Fold gently and keep as much air in the mixture as possible to ensure your semifreddo stays light.
Pour mixture into the container, then cover with the overhanging wrap and freeze for about 6 hours or until firm.
When ready to serve, turn semifreddo out onto a platter, then slice and serve with almond biscotti, dusted with cocoa powder.