Line a 6-inch x 9-inch (15cm x 23cm) rectangle loaf pan with 2 layers of cling film, allowing extra cling film to hang over the sides. Set aside.
Prepare a large pot and half fill with water, bring to a simmer.
Meanwhile, in a large heat-proof mixing bowl, add egg yolks, whole egg, vanilla and sugar.
Once water is slowly simmering, sit bowl with egg mixture into the pot, ensuring the bottom of the bowl isn’t touching the water.
Using a hand-held electric beater/whisk, beat egg mixture over the steaming water for 4-6 minutes or until mixture is thick and pale, this can happen fast so keep an eye on your mixture.
Once thick and pale, remove from heat and set aside.
In a separate mixing bowl, add thickened cream and using a hand-held electric beater/whisk, beat cream to firm peaks.
Spoon whipped cream into thick egg mixture, gently fold until combined.
Add raspberries and fold through until just combined, creating a raspberry swirl effect.
Pour a 1/4 of the mixture into lined pan.
Drizzle over half the melted chocolate.
Pour another 1/4 of the mixture in the pan over the chocolate.
Drizzle over remaining chocolate.
Pour in remaining mixture and smooth out top.
Fold over the excess cling film from the sides to cover the semifreddo, or cover with new cling film.
Place in freezer to set for 6 hours or preferably overnight.
Semifreddo will not be completely hard, it will be set.
To serve, remove semifreddo from pan by picking it out using the cling film. Turn out onto a serving plate/platter. Remove cling film completely.
Top with fresh cherries and a dusting of sifted icing sugar.
Slice, serve and enjoy!
Notes
Store semifreddo in an airtight container, in the freezer, for 1-2 weeks.