Preheat the oven to 180˚C/Fan 160˚C/Gas 4. Put the hazelnuts on a small baking tray and roast for 8 minutes or until golden; set aside to cool. Meanwhile, grease and line the base and sides of 2 loose-bottomed 18cm sandwich cake tins. Put the cooled hazelnuts and 1 tbsp caster sugar in a small food processor; pulse until ground (a few chunky pieces are fine).
Put the egg whites and a pinch of salt in a mixing bowl. Using electric beaters, whisk to stiff peaks, then whisk in 150g caster sugar in 3 additions. Fold through the ground hazelnuts and vinegar, divide between the tins, smoothing the tops, then bake for 30-35 minutes. Set aside to cool.
Using electric beaters, whisk the cream, remaining 1 tbsp sugar and vanilla to soft peaks. Stir in the yogurt. Remove the meringue cakes from the tins; place one on a cake stand. Spread with half of the cream mixture and tumble over half of the strawberries. Repeat with a second layer and serve at once.