With the rack in the middle position, preheat the oven to 135 °C (275 °F). Line a baking sheet with parchment paper. With a pencil, draw two circles on the paper with the bottom of a 20 cm (8-inch) springform pan. Return the sheet to avoid contact of the ink or lead with the meringue. Set aside.
In a food processor, finely grind the pistachios with the cornstarch. Set aside.
In a large bowl, beat the egg whites with an electric mixer until they form soft peaks. Gradually add the sugar and beat until the meringue forms stiff peaks. With a spatula, gently fold the pistachio mixture into the meringue.
With a pastry bag or a spatula, spread the meringue inside the two circles on the baking sheet. Bake for 30 minutes or until the meringue is dry. Let cool completely.
In a 20 cm (8-inch) springform pan, place a meringue disc. If needed, cut to fit. Cover with half of the ice cream. Layer with the sorbet. Add the second disc of meringue. Cover with the remaining ice cream. Press lightly. Freezing for 4 hours.
In a bowl, combine the raspberries and sugar. Let rest for 15 minutes or until the raspberries release some juice.
When ready to serve, cut the cake into wedges and garnish with the stewed raspberries.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.