Preheat the oven to 180˚C, gas mark 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 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 ½ the cream mixture and tumble over ½ the strawberries. Repeat with a second layer and serve at once.
Cook’s tip
Don’t grind the hazelnuts for too long in the food processor, otherwise they’ll become oily (and eventually turn to nut butter). Just pulse them until they’re quite finely ground.
