1.Line a 21cm x 11cm loaf pan with a double layer of plastic wrap, allowing a 5cm overhang of wrap on all sides.
2.Place 300g of raspberries in a food processor and process until pureed. Pass through a fine sieve into a medium bowl, pressing with the back of a spoon. Discard seeds.
3.Using an electric mixer, beat cream and vanilla in a large bowl until soft peaks form.
4.Combine sugar and 1 1/2 tbsp water in a small saucepan. Place over low heat and stir for 1-2 minutes or until sugar dissolves. Increase heat to medium and bring to a boil. Boil, without stirring, for 2 minutes. Remove from heat.
5.Using an electric mixer, beat egg whites in a clean dry bowl until stiff peaks form. Gradually beat in sugar syrup until thick and glossy.
6.Fold meringue mixture into cream mixture until combined. Transfer half to a separate bowl. Add raspberry puree to one bowl and fold until combined. Cover with plastic wrap and chill.
7.Pour remaining cream mixture into prepared pan and smooth surface. Scatter remaining raspberries over cream mixture and freeze for 1 1/2 hours or until firm. Pour chilled raspberry mixture over ice-cream in pan and smooth surface. Fold over plastic wrap to cover, and freeze for a further 3 hours or until firm.
8.Before serving, remove parfait from freezer and stand at room temperature for 20 minutes or until slightly softened. To serve, invert onto a serving plate, remove plastic wrap and slice.