Recipe adapted from Donna Hay
4 oz of blackberries
Pinch of salt
2 yolks, extra
1 teaspoon of vanilla extract
3/4 cup of granulated sugar
2 cups of heavy whipping cream
Pre-chill a 2-quart (or 2-litre) capacity metal tin in the freezer.
For the puree, add the blackberries and pinch of salt to the food processor until smooth. Set aside.
Place eggs, extra yolks, vanilla extract and sugar in a heatproof bowl over a saucepan of simmering water and, either by hand or using a hand-held electric mixer, beat for 6-8 mins, until thick and pale and 160F degrees. Remove from heat and beat for a further 6-8 mins or until cool (you can transfer to a standing mixer instead and whip for about 4 minutes).
Whisk the cream until medium-stiff peaks form. Gently fold cream through the egg mixture until well combined. Pour into a 2-litre capacity metal tin.
Spoon over the blackberry purée and use a spatula to gently fold it through the cream mixture for a swirled effect. Freeze for 6 hours or overnight before serving. Top with extra blackberries and serve with a few tablespoons of blackberry puree.