1. Using an electric mixer, beat butter, sugar, lemon rind and vanilla seeds until pale and fluffy. Add eggs one at a time, beating well between additions.
2. Fold in the combined flour, baking powder, semolina and almond meal, alternately with the yoghurt.
3. Spoon batter into a buttered, base-lined 24cm cake tin. Bake at 180°C for 50-55 minutes, or until cooked when tested with a skewer.
4. To make Syrupy Lemons, combine sugar, water and reserved vanilla pod in a saucepan and stir until sugar dissolves. Bring to the boil and simmer for 3-4 minutes. Add lemon slices, reduce heat and cook for a further 5 minutes or until lemons are tender. Remove lemons from syrup and cool.
5. Cool cake in tin for 10 minutes, before drizzling with 3/4 of the cooled syrup. Stand for a further 10 minutes before turning onto a cooling rack and decorate with lemon slices. Serve each slice with a dollop of extra yoghurt and remaining syrup.
When making syrup cakes make sure that the cake is warm and the syrup is cool before drizzling (or vice versa).