Preheat the oven to 180 degrees C

Grease and line a 23cm springform pan with baking paper

Use an electric mixer and beat the egg whites until soft peaks form - about 5 minutes - and set aside

In a separate bowl, using the same mixer, combine the egg yolks and sugar and beat on a medium-high speed until the mixture is pale and fluffy, about 5 minutes

Mix in the flour, yoghurt, lemon zest and juice, and salt until fully incorporated

Gently fold in half of the egg whites into the yoghurt

Then fold in the remaining whites, scraping the bottom and sides of the bowl, until the batter is evenly mixed

Pour into the prepared pan and smooth the top

Bake until the top golden brown, puffed and just firm to the touch, about 45 minutes

The cake will puff up and fall like a souffle once removed from the oven

Let the cake cool before removing from the pan and serve at room temperature or cold