2 egg yolks, extra
1 vanilla bean, split and seeds scraped
1 cup caster sugar
1¾ cups single
1. Place the raspberries in the bowl of a small food processor and process until smooth. Set aside.
2. Place the eggs, egg yolks, vanilla and sugar in a large heatproof bowl. Place over a saucepan of simmering water and whisk the mixture with a hand-held beater for 4-5 minutes or until thick and pale. Remove from the heat and continue whisking until cool.
3. Whisk the cream until soft peaks form and gently fold into the egg mixture. Reserve 2 cups of the mixture and pour the remainder into a 3-litre-capacity (12-cup) dish.
4. Fold the reserved mixture through the pureed raspberries and spoon stripes over the semifreddo. Place in the freezer for 4-6 hours or until set.