To prepare the syrup, add all the ingredients for the syrup in a small pot and bring to the boil. Boil for about 2-3 minutes, until the sugar has dissolved and the syrup has slightly thickened. Leave aside to cool.

Divide the eggs into yolks and whites. Place the egg whites in the mixer's bowl, along with a pinch of salt. Make sure your egg whites, bowl and whisk attachments are clean and free of any water. Whisk the egg whites until the mixture is very thick and glossy and a long trailing peak forms when the whisk is lifted (meringues). Place the mixture in a bowl and set aside.

In another bowl, sift the flour and the baking powder and blend.

Use an electric mixer, to mix the butter and sugar for about 15 minutes, until the butter is creamy and fluffy. Add the egg yolks, one at a time, whilst mixing, allowing time for each one to be absorbed, before adding another. Add the yogurt, the orange and lemon zest and the vanilla extract and blend to combine. Add 1/3 of the sifted flour and blend, using a maryse spatula. Add 1/3 of the meringues and blend with light circular movements from the bottom up. Repeat with the rest of the flour and meringue.

Preheat the oven to 190C. Butter the bottom and sides of a 26cm round cake tin and pour in the mixture.

Place the cake in the preheated oven, on the lower rack, turn the heat down to 175C and bake for 50-60 minutes, until nicely coloured and cooked through. Check if it is ready by inserting a wooden skewer or toothpick in the middle - it should come out clean.

Ladle slowly the cold syrup over the hot cake, allowing each ladle of the syrup to be absorbed before adding more.

Serve cold with fresh fruits, yogurt or ice-cream.