Turkish Yoghurt Cake

Directions

1. 1
   Preheat the oven to 350°F / 175°C.
2. 2
   Beat the egg yolks with the sugar to a thick, pale cream.
3. 3
   Beat in the flour, then the yoghurt, lemon zest, and lemon juice until it is thoroughly blended.
4. 4
   Whisk the egg whites until stiff and fold them into the yoghurt mixture.
5. 5
   Pour this into a round, nonstick baking tin (about 9 inches in diameter), greased with butter.
6. 6
   Bake for 50 to 60 minutes, until the top is brown. It will puff up like a souffle and then subside. Turn out onto a serving plate, and serve warm or cold.