Preheat your oven to 180°C (350°F/Gas 4). Grease and flour a 22 cm (9 inch) square cake tin. Cream the butter and sugar together in a large bowl with electric beaters. Whisk in the yoghurt, rose water, egg yolks and lime rind. Sift in the flour, semolina and baking powder and mix well to incorporate. Mix in the ground almonds. In a separate bowl, whisk the egg whites until they are white, fluffy and just making soft peaks. Carefully fold these into the mixture so that they are well incorporated. Pour the batter into the tin and bake for about 45 minutes, or until the cake is deep golden and cooked through. Leave to cool while making the syrup.
To make the syrup, put the sugar, rose water and 250 ml (1 cup) of water in a small saucepan and boil for about 5 minutes. Pour the hot syrup over the cake and leave it to cool completely. To serve, cut the cake into small pieces and serve with a not-too-sweet ice cream (such as the mastika ice cream overleaf).