Semifreddo

Method

1. Line a small mould or ramekin of about 200 ml with cling film, pressing it into the corners and leaving a generous overhang on all sides. Put it in the freezer to chill while you work.
2. Whip the 80 ml of well-chilled double cream with the 0.25 tsp of vanilla extract in a cold bowl, by hand or with a hand whisk, until it holds soft, floppy peaks — stop before it stiffens or the semifreddo will taste buttery. Cover and refrigerate.
3. Bring a small pan of water to a bare simmer. In a heatproof bowl that sits over it without touching the water, whisk 1 egg yolk with the 30 g of caster sugar, the 1 tbsp of water and a pinch of salt. Whisk steadily over the heat for 6-8 minutes, until the zabaione has tripled in volume, is pale and thick and falls from the whisk in a slow ribbon that sits on the surface for a second (about 70C).