Heat the oven to 120°C/fan 100°C/gas ½. Grease and line a large baking sheet with baking paper.

In a squeaky-clean bowl, beat the egg whites with an electric hand mixer until soft peaks form. Add the sugar, 1tbsp at a time, beating until it dissolves and the mixture is stiff and glossy. Add the vinegar, cornflour and vanilla extract, then beat for another 30 sec or until the mixture combines.

Spoon the meringue on to the baking sheet, then spread out to a 23cm diameter circle. Bring the sides up with a spatula to create a wall. Bake for 1 hr 30 min or until just firm to touch. Turn off the oven and open the door slightly, leaving the meringue inside to cool.

Whisk the ricotta until smooth, then whisk in the yogurt.

Put half the raspberries and the remaining 2 tablespoons sugar in a food processor and blend until smooth. Pass the sauce through a fine sieve to remove the seeds.

Put the cooled meringue on a cake stand or serving plate. Top with the ricotta mixture, scatter over the remaining berries and drizzle over the raspberry sauce.