Steps
1. In a heatproof bowl, whisk egg yolks with half the sugar until pale.
2. Place the bowl over simmering water and whisk continuously until the mixture thickens to a custard-like consistency. Remove from heat and let cool.
3. In a separate clean bowl, whisk egg whites with a pinch of salt until soft peaks form. Gradually add the remaining sugar and whisk until stiff peaks.
4. In another bowl, whip the heavy cream until soft peaks form.
5. Gently fold the cooled egg yolk mixture with raspberry liqueur, vodka, and pineapple juice.
6. Carefully fold in the whipped cream.
7. Lastly, fold in the egg whites gently to retain airiness.
8. Pour the mixture into a loaf pan lined with cling film.
9. Freeze for at least 6 hours or overnight until semi-frozen.
10. To serve, unmold the semifreddo onto a plate and garnish with fresh raspberries.